ke kālaikūlohea

1. Hāʻule kūʻokoʻa ke kino 1-kg mai ka hoʻomaha ʻana, mai ke kiʻekiʻe o 80 m. ʻO ka wikiwiki ma muli o ke koʻikoʻi he 10 m/s ^2. He aha ka ikehu kinetic ke paʻi ke kino i ka honua.

ʻIke ʻia:

Nuipaʻa (m) = 1 kg

Kiʻekiʻe (h) = 80 m

Ka wikiwiki ma muli o ke koʻikoʻi (g) = 10 m/s ²

Makemake ʻia: ikehu kinetic ke paʻi ke kino i ka honua

Lōlā:

ʻO ka ikehu mechanical mua (ME _o ) = ka ikehu hiki ke hoʻopaʻa ʻia e ka umekaumaha (PE)

ME o ₌ PE = mgh = (1)(10)(80) = 800 Joules

ʻO ka ikehu mechanical hope loa (M E _t ) = ikehu kinetic (K E )

ʻO ke kumumanaʻo o ka mālama ʻana i ka ikehu mechanical :

ME o = ME _t​

P E = K E

800 = K E

ʻO ka ikehu kinetic hope loa he 800 Joules.

ʻAʻole maopopo

2. Hāʻule kūʻokoʻa ke kino 4-kg mai ka hoʻomaha ʻana, mai ke kiʻekiʻe o 10 m. ʻO ka wikiwiki ma muli o ke koʻikoʻi he 10 ms ^–2 . He aha ka ikehu kinetic a me ka wikiwiki ma 5 mika ma luna o ka honua.

ʻIke ʻia:

ʻO ka loli o ke kiʻekiʻe (h) = 10 – 5 = 5 mika s

Nuipaʻa (m) = 4 kg

Ka wikiwiki ma muli o ke koʻikoʻi (g) = 10 m/s ²

Makemake ʻia: Ikehu kinetic ma 5 mika ma luna o ka honua a me ka wikiwiki ma 5 mika ma luna o ka honua

Lōlā:

(a) Ikehu kinetic ma 5 mika ma luna o ka honua

ʻO ka ikehu mechanical mua (M E _o ) = ka ikehu hiki ke hoʻouluulu ʻia (P E )

ME o ₌ PE = mgh = (4)(10)(5) = 200 Joules

ʻO ka ikehu mechanical hope loa (EM _t ) = ikehu kinetic (EK)

M E _t = K E

ʻŌlelo ke kumumanaʻo o ka mālama ʻana i ka ikehu mechanical ʻo ka ikehu mechanical mua = ka ikehu mechanical hope loa.

ME o = ME _t​

200 = K E

ʻO ka ikehu kinetic ma 5 mika ma luna o ka honua he 200 Joules.

(b) ka wikiwiki ma 5 mika ma luna o ka honua

ʻO ka ikehu mechanical mua (M E _o ) = ka ikehu mechanical hope loa (M E _t )

P E = K E

200 = ½ mv ²

2(200) / 4 = v ²

100 = v ²

v = √100

v = 10 m/s

ʻO ka wikiwiki o ke kino ma 5 mika ma luna o ka honua he 10 m/s.

ʻAʻole maopopo

3. Hāʻule kūʻokoʻa kahi mango mai ka hoʻomaha ʻana, mai ke kiʻekiʻe o 2 mika. ʻO ka wikiwiki ma muli o ke koʻikoʻi he 10 ms ^–2 . E hoʻoholo i ka wikiwiki o ka mango ke pā i ka honua.

ʻIke ʻia:

Kiʻekiʻe (h) = 2 mika s

Ka wikiwiki ma muli o ke koʻikoʻi (g) = 10 m/s ²

Makemake ʻia: ka wikiwiki o ka mango ke pā i ka honua.

Lōlā:

ʻO ka ikehu mechanical mua (M E _o ) = ka ikehu hiki ke hoʻouluulu ʻia (P E )

M E = P E = mgh = m (10)(2) = 20 m

ʻO ka ikehu mechanical hope loa (M E _t ) = ka ikehu kinetic (K E )

M E _t = KE = ½ mv ²

ʻŌlelo ke kumumanaʻo o ka mālama ʻana i ka ikehu mechanical ʻo ka ikehu mechanical mua = ka ikehu mechanical hope loa.

ME o = ME _t​

20 m = ½ mv ²

20 = ½ v ²

2(20) = v ²

40 = v ²

v = √40 = √(4)(10) = 2√10 m/ s

[wpdm_package id='1166′]

1. Nā pilikia hana i hana ʻia e ka ikaika a me nā hoʻonā
2. Nā pilikia a me nā hoʻonā o ka ikehu hana-kinetic
3. Nā pilikia a me nā hoʻonā i nā kumumanaʻo ikehu hana-mekanika
4. Nā pilikia ikehu hiki ke umekaumaha a me nā hoʻonā
5. ʻO ka ikehu hiki ke loaʻa i nā pilikia a me nā hoʻonā o ka pūnāwai elastic
6. Nā pilikia mana a me nā hoʻonā
7. Ka hoʻohana ʻana i ka mālama ʻana i ka ikehu mechanical no ka neʻe hāʻule manuahi
8. Ka hoʻohana ʻana i ka mālama ʻana i ka ikehu mechanical no ka neʻe ʻana i luna a i lalo i ka neʻe hāʻule manuahi
9. Ka hoʻohana ʻana i ka mālama ʻana i ka ikehu mechanical no ka neʻe ʻana ma luna o kahi ʻili kūlou
10. Ka hoʻohana ʻana i ka mālama ʻana i ka ikehu mechanical no ka neʻe ʻana ma kahi mokulele inclined
11. Ka hoʻohana ʻana i ka mālama ʻana i ka ikehu mechanical no ka neʻe ʻana o ka projectile

heluhelu hou

1. Hoʻolei kekahi kanaka i kahi pōhaku 1-kg i luna ma 2 m/s ʻoiai e kū ana ma ka lihi o ka pali i hiki ai i ka pōhaku ke hāʻule i ke kumu o ka pali he 40 mika ma lalo. He aha ka ikehu kinetic o ka pōhaku ma 10 mika ma luna o ka honua? Ka wikiwiki ma muli o ke koʻikoʻi g = 10 m/ ^s2.

ʻIke ʻia:

Nuipaʻa (m) = 1 kg

Ka wikiwiki mua (v _o ) = 2 m/s

ʻO ka loli o ke kiʻekiʻe = 40 – 10 = 30 mika

Ka wikiwiki ma muli o ke koʻikoʻi (g) = 10 m/s ²

Makemake ʻia: ikehu kinetic o ka pōhaku ma 10 mika ma luna o ka honua

Lōlā:

ʻO ka ikehu mechanical mua

ʻO ka ikehu hiki ke hoʻohana ʻia e ka umekaumaha mua (EP) = mgh = (1)(10)(30) = 300 Joules

ʻO ka ikehu kinetic mua (KE) = ½ mv _o ² = ½ (1)(2) ² = ½ (4) = 2 Joules

ʻO ka ikehu mechanical mua = ka ikehu hiki ke umekaumaha mua + ka ikehu kinetic mua = 300 + 2 = 302 Joules.

ʻO ka ikehu mīkini hope loa

ʻO ka ikehu mechanical hope loa = ka ikehu kinetic hope loa = ka ikehu hiki ke umekaumaha mua + ka ikehu kinetic mua = 300 + 2 = 302 Joules.

ʻAʻole maopopo

2. Hoʻolei kekahi kanaka i kahi mea 1-kg i luna i ka lewa me ka wikiwiki mua o 10 m/s. E hoʻoholo (a) ka ikehu hiki ke hoʻopaʻa ʻia ma ke kiʻekiʻe loa (b) ke kiʻekiʻe loa.

ʻO ka wikiwiki ma muli o ke koʻikoʻi he 10 m/s ²

ʻIke ʻia:

Nuipaʻa (m) = 1 kg

Ka wikiwiki mua (v _o ) = 10 m/s

Ka wikiwiki ma muli o ke koʻikoʻi (g) = 10 m/s ²

Makemake ʻia : ka ikehu hiki ke hoʻopaʻa ʻia ma ke kiʻekiʻe loa a me ke kiʻekiʻe loa

Lōlā:

(a) ka ikehu hiki ke hoʻopaʻa ʻia ma ke kiʻekiʻe loa

ʻO ka ikehu mechanical mua:

ʻO ka ikehu mechanical mua (ME) = ka ikehu kinetic mua (KE) = ½ mv _o ² = ½ (1)(10) ² = ½ (100) = 50 Joules.

Ka ikehu mīkini hope loa:

ʻO ka ikehu mechanical hope loa (ME) = ka ikehu hiki ke hoʻopaʻa ʻia e ka umekaumaha (PE)

ʻO ke kumumanaʻo o ka mālama ʻana i ka ikehu mechanical:

ʻO ka ikehu mechanical mua = ka ikehu mechanical hope loa

KE = PE

50 = PE

ʻO ka ikehu hiki ke hoʻoulu ʻia e ka umekaumaha he 50 Joules.

(b) Ke kiʻekiʻe loa

PE = mgh

50 = (1)(10) hola

50 = 10 hola

h = 50 / 10 = 5 mika

ʻO ke kiʻekiʻe loa he 5 mika ma luna o ka honua.

[wpdm_package id='1174′]

1. Nā pilikia hana i hana ʻia e ka ikaika a me nā hoʻonā
2. Nā pilikia a me nā hoʻonā o ka ikehu hana-kinetic
3. Nā pilikia a me nā hoʻonā i nā kumumanaʻo ikehu hana-mekanika
4. Nā pilikia ikehu hiki ke umekaumaha a me nā hoʻonā
5. ʻO ka ikehu hiki ke loaʻa i nā pilikia a me nā hoʻonā o ka pūnāwai elastic
6. Nā pilikia mana a me nā hoʻonā
7. Ka hoʻohana ʻana i ka mālama ʻana i ka ikehu mechanical no ka neʻe hāʻule manuahi
8. Ka hoʻohana ʻana i ka mālama ʻana i ka ikehu mechanical no ka neʻe ʻana i luna a i lalo i ka neʻe hāʻule manuahi
9. Ka hoʻohana ʻana i ka mālama ʻana i ka ikehu mechanical no ka neʻe ʻana ma luna o ka ʻili piʻo
10. Ka hoʻohana ʻana i ka mālama ʻana i ka ikehu mechanical no ka neʻe ʻana ma kahi mokulele inclined
11. Ka hoʻohana ʻana i ka mālama ʻana i ka ikehu mechanical no ka neʻe ʻana o ka projectile

heluhelu hou

1. Hoʻopili ʻia kahi nuipa 2-kg i kahi pūnāwai. Inā he 4 cm ka lōʻihi o ka pūnāwai, e hoʻoholo i ka ikehu hiki o ka pūnāwai elastic . ʻO ka wikiwiki ma muli o ke kaumaha he 10 m/s ².

ʻIke ʻia:

Nuipaʻa (m) = 2 kg

Ka wikiwiki ma muli o ke koʻikoʻi (g) = 10 m/s ²

Kaumaha (w) = mg = (2)(10) = 20 N

Hoʻolōʻihi (x) = 4 kenimika = 0.04 m

Makemake ʻia: Ka ikehu hiki o ka pūnāwai elastic

Lōlā:

ʻO ke ʻano o ke kānāwai o Hooke :

F = kx

F = ikaika, k = kūpaʻa puna, x = ka loli o ka lōʻihi o ka puna

Paʻa mau o ka pūnāwai:

k = w / x = 20 / 0.04 = 500 N/m

Ka ikehu hiki o ka pūnāwai elastic:

PE = ½ kx ² = ½ (500)(0.04) ² = (250)(0.0016) = 0.4 Joule

Hoʻonā ʻē aʻe:

PE = ½ kx ² = ½ (w / x) x ² = ½ wx = ½ mgx

w = kaumaha, m = nuipa, x = ka loli o ka lōʻihi o ka pūnāwai

PE = ½ (2)(10)(0.04) = (10)(0.04) = 0.4 Joule.

ʻAʻole maopopo

2. ʻO ka elongation o ka pūnāwai i hohola ʻia e ka ikaika F = 50 N he 10 cm. He aha ka ikehu hiki o ka pūnāwai elastic inā he 12 cm ka elongation o ka pūnāwai.

ʻIke ʻia:

Hoʻolōʻihi (x) = 10 kenimika = 0.1 m

Ikaika (F) = 50 N

Makemake ʻia : Ka ikehu hiki o ka pūnāwai elastic

Lōlā:

Paʻa mau o ka pūnāwai:

k = F / x = 50 / 0.1 = 500 N/m

ʻO ka ikehu hiki o ka pūnāwai elastic inā he 12 kenimika ka elongation o ka pūnāwai.:

PE = ½ kx ² = ½ (500)(0.12) ² = (250)(0.0144) = 3.6 Joule.

ʻAʻole maopopo

3. Kiʻi o F vs x i hōʻike ʻia ma ke kiʻi ma lalo nei. He aha ka ikehu hiki o ka pūnāwai elastic, inā he 10 cm ka elongation o ka pūnāwai.

ʻIke ʻia:

Ikaika (F) = 5 N

ʻO ka hoʻolōʻihi ʻana o ka pūnāwai (x) = 2 kenimika = 0.02 m

Makemake ʻia: ʻO ka ikehu hiki o ka pūnāwai elastic inā he 0.1 m ka elongation o ka pūnāwai.

Lōlā:

Paʻa mau o ka pūnāwai:

k = F / x = 5 / 0.02 = 250 N/m

ʻO ka ikehu hiki o ka pūnāwai elastic inā he 0.1 m ka elongation o ka pūnāwai:

PE = ½ kx ² = ½ (250)(0.1) ² = (125)(0.01) = 1.25 Joule.

4. Lele kekahi mea pāʻani ma luna o kahi mea kani puna me ke kaumaha o 500 N, hoʻopōkole ka puna i 4 kenimika. E hoʻoholo i ka nui o ka ikehu hiki ke hoʻoikaika i ka mea pāʻani.

A. 20 Joule

B. 10 Joule

C. 5 Joule

D. 2 Joule

ʻIke ʻia:

Ikaika (F) = 500 N

ʻO ka loli o ka lōʻihi o ka pūnāwai (Δx) = 4 kenimika = 0.04 m

Makemake ʻia: Ka ikehu hiki o ka pūnāwai

Lōlā:

E helu i ke kūpaʻa elastic o kahi pūnāwai me ka hoʻohana ʻana i ka hoohalike o ke kānāwai o Hooke:

k = F / Δx = 500 N / 0.04 m = 12500 N/m

ʻO ka ikehu hiki ke hoʻololi ʻia o ka pūnāwai:

PE = ½ k Δx ² = ½ (12500)(0.04) ² = (6250)(0.0016)

PE = 10 Joule

ʻO ka pane pololei ʻo B.

5. He pūnāwai ke kau ʻia me ka nuipa o 500 grams, e piʻi aʻe kona lōʻihi ma 5 cm. E hoʻoholo i kona kūpaʻa a me kona ikehu hiki.

ʻIke ʻia:

Ka nuipa o ka mea (m) = 500 grams = (500/1000) kg = 5/10 kg = 0.5 kg

Hoʻolalelale (g) = 10 m/s ²

Kaumaha o ka mea (w) = mg = (0.5 kg)(10 m/s ² ) = 5 kg m/s ² = 5 Newtons

ʻO ka loli o ka lōʻihi o ka pūnāwai (Δx) = 5 kenimika = 0.05 m

Makemake ʻia: ke kūpaʻa o ka pūnāwai (k) a me ka ikehu hiki (PE)

Lōlā:

ʻO ka mea mua, e helu i ke kūpaʻa o ka pūnāwai me ka hoʻohana ʻana i ka hoohalike o ke kānāwai o Hooke:

k = w / Δx = 5 N / 0.05 m = 100 N/m

ʻO ka hiki ke hoʻopili ʻia o ka pūnāwai:

PE = ½ k Δx ² = ½ (100)(0.05) ² = (50)(0.0025)

PE = 0.125 Joule

[wpdm_package id='1179′]

1. Nā pilikia hana i hana ʻia e ka ikaika a me nā hoʻonā
2. Nā pilikia a me nā hoʻonā o ka ikehu hana-kinetic
3. Nā pilikia a me nā hoʻonā i nā kumumanaʻo ikehu hana-mekanika
4. Nā pilikia ikehu hiki ke umekaumaha a me nā hoʻonā
5. Ka ikehu hiki ke loaʻa o nā pilikia a me nā hoʻonā o ka pūnāwai elastic
6. Nā pilikia mana a me nā hoʻonā
7. Ka hoʻohana ʻana i ka mālama ʻana i ka ikehu mechanical no ka neʻe hāʻule manuahi
8. Ka hoʻohana ʻana i ka mālama ʻana i ka ikehu mechanical no ka neʻe ʻana i luna a i lalo i ka neʻe hāʻule manuahi
9. Ka hoʻohana ʻana i ka mālama ʻana i ka ikehu mechanical no ka neʻe ʻana ma nā ʻili piʻo
10. Ka hoʻohana ʻana i ka mālama ʻana i ka ikehu mechanical no ka neʻe ʻana ma ka mokulele inclined
11. Ka hoʻohana ʻana i ka mālama ʻana i ka ikehu mechanical no ka neʻe ʻana o ka projectile

heluhelu hou

1. He hāʻule kūʻokoʻa o ke kino 1-kg mai ka hoʻomaha ʻana, mai ke kiʻekiʻe o 10 m.

E hoʻoholo:

(a) Hana i hana ʻia e ka ikaika o ke koʻikoʻi

(b) Ka loli o ka ikehu hiki ke hoʻopaʻa ʻia

Ka wikiwiki ma muli o ke koʻikoʻi (g) = 10 m/s ²

ʻIke ʻia:

Nuipaʻa (m) = 1 kg

Kiʻekiʻe (h) = 10 m

Ka wikiwiki ma muli o ke koʻikoʻi (g) = 10 m/s ²

Kaumaha (w) = mg = (1 kg)(10 m/s ² ) = 10 N

Lōlā:

(a) Hana i hana ʻia e ka ikaika o ke koʻikoʻi

W = wh = mgh

W = (1)(10)(10) = 100 Joule

(b) Ka loli o ka ikehu hiki ke hoʻopaʻa ʻia

Ua like ka loli o ka ikehu hiki ke umekaumaha me ka hana i hana ʻia e ka umekaumaha.

Δ EP = 100 Joule

ʻAʻole maopopo

2. Heʻe iho kahi mea 10 N ma luna o ka mokulele hilig laumania ma ke ʻano he 2 mika. E hoʻoholo i ka hana i hana ʻia e ka ikaika kaumaha!

ʻIke ʻia:

kaumaha (w) = 10 N

w _x = w hewa θ = (10)(hala 30 ^o ) = (10)(0.5) = 5 N

d = 2 m

Ka wikiwiki ma muli o ke koʻikoʻi (g) = 10 m/s ²

Makemake ʻia: hana i hana ʻia e ka ikaika kaumaha

Lōlā:

W = F d = w _x d = (5)(2) = 10 Joules

Hoʻonā ʻē aʻe:

Sin 30 ^o = h / d

0.5 = h / 2

h = (0.5)(2)

h = 1 mika

Hana i hana ʻia e ka ikaika kaumaha;

W = F d = wh = (10 N)(1 m) = 10 N m = 10 Joules

ʻAʻole maopopo

3. He mea 1,500 gram ma 20 mika ma luna o ka honua , hāʻule manuahi i ka honua. He aha ka ikehu hiki ke hoʻopaʻa ʻia o ka mea. ʻO ka wikiwiki ma muli o ke koʻikoʻi he 10 m/ ^s².

ʻIke ʻia:

Ka wikiwiki ma muli o ke koʻikoʻi (g) = 10 m/s ²

Nuipaʻa (m) = 1500 grams = 1500/1000 kilokani = 1.5 kilokani

Kiʻekiʻe (h) = 20 mika

Makemake ʻia: Ka ikehu hiki ke hoʻopaʻa ʻia

Lōlā:

PE = mgh = (1.5 kg)(10 m/s ² )(20 m) = 300 kg m ² /s ² = 300 Joules

4. Ma muli o ke kiʻi ma lalo nei, inā he 2 kg ka nui o ka mea 1 a he 4 kg ka nui o ka mea 2, ʻo ka hoʻohālikelike ʻana o ka ikehu hiki o ka mea 1 a me ka mea 2 he …..

ʻIke ʻia:

Ka nuipa o ka mea 1 (m₁) = 2 kilokani

Ka nuipa o ka mea 2 (m2 ₎ = 4 kilokani

Kiʻekiʻe 1 (h ₁ ) = 12 mika

Kiʻekiʻe 2 (h ₂ ) = 9 mika

Makemake ʻia: Hoʻohālikelike ʻana o ka ikehu hiki o ka mea 1 a me ka mea 2

Lōlā:

PE = mgh

m = ka nuipa (ʻo kona anakahi honua he kilokani, i hoʻopōkole ʻia kg)

g = ka wikiwiki ma muli o ke koʻikoʻi (ʻo kona anakahi honua he mika no kekona kuea, i hoʻopōkole ʻia m/s ² )

h = ke kiʻekiʻe (ʻo kona anakahi honua he mika, i hoʻopōkole ʻia ʻo m)

PE = ikehu hiki ke hoʻohana ʻia ka umekaumaha (ʻo kona anakahi honua he kg m² ^/ s² ^a i ʻole Joule)

ʻO ka ikehu hiki ke hoʻohana ʻia e ka umekaumaha o ka mea 1:

EP ₁ = m ₁ gh ₁ = (2)(g)(12) = 24 g

ʻO ka ikehu hiki ke hoʻohana ʻia e ka umekaumaha o ka mea 2:

EP ₂ = m ₂ gh ₂ = (4)(g)(9) = 36 g

Hoʻohālikelike ʻana o ka ikehu hiki o ka mea 1 a me ka mea 2:

PE ₁ : PE ₂

24 g : 36 g

24: 36

24/12 : 36/12

2: 3

[wpdm_package id='1175′]

1. Nā pilikia hana i hana ʻia e ka ikaika a me nā hoʻonā
2. Nā pilikia a me nā hoʻonā o ka ikehu hana-kinetic
3. Nā pilikia a me nā hoʻonā i nā kumumanaʻo ikehu hana-mekanika
4. Nā pilikia ikehu hiki ke umekaumaha a me nā hoʻonā
5. ʻO ka ikehu hiki ke loaʻa i nā pilikia a me nā hoʻonā o ka pūnāwai elastic
6. Nā pilikia mana a me nā hoʻonā
7. Ka hoʻohana ʻana i ka mālama ʻana i ka ikehu mechanical no ka neʻe hāʻule manuahi
8. Ka hoʻohana ʻana i ka mālama ʻana i ka ikehu mechanical no ka neʻe ʻana i luna a i lalo i ka neʻe hāʻule manuahi
9. Ka hoʻohana ʻana i ka mālama ʻana i ka ikehu mechanical no ka neʻe ʻana ma luna o kahi ʻili kūlou
10. Ka hoʻohana ʻana i ka mālama ʻana i ka ikehu mechanical no ka neʻe ʻana ma kahi mokulele inclined
11. Ka hoʻohana ʻana i ka mālama ʻana i ka ikehu mechanical no ka neʻe ʻana o ka projectile

heluhelu hou

1. Hoʻoemi ka wikiwiki o kahi pahu 2-kg mai 10 m/s a i ka hoʻomaha. ʻO ke koina o ka friction kinetic he 0.2. ʻO ka wikiwiki ma muli o ke koʻikoʻi he 10 m/s ^2. He aha ka nui o ka neʻe ʻana?

ʻIke ʻia;

Nuipaʻa (m) = 2 kg

Ka wikiwiki mua (v _o ) = 10 m/s

Ka wikiwiki hope loa (vt ₎ = 0 m/s

ʻO ke koina o ka friction kinetic ( _μk ) = 0.2

Kaumaha (w) = mg = (1 kg)(10 m/s ² ) = 10 kg m/s ² = 10 N

Makemake ʻia: Ka nui o ka neʻe ʻana (d)

Lōlā:

ʻO ke kumumanaʻo o ka hana-ikaika mechanical :

W _nc = ΔEM

W _nc = ΔEK + ΔEP

W _nc = ½ m (v _t ² – v _o ² ) + mgh

W _nc = hana i hana ʻia e ka ikaika nonconservative e hana ana ma luna o ka mea

ΔEK = ka loli o ka ikehu kinetic

ΔEP = ka loli o ka ikehu hiki

m = ka nuipa

v = ka wikiwiki

g = ka wikiwiki ma muli o ke koʻikoʻi

h = ka loli o ke kiʻekiʻe

ʻO ka loli o ke kiʻekiʻe h = 0 no laila ΔEP = 0

W _nc = ΔEK

Nā hana i hana ʻia e ka ikaika mālama ʻole:

W _nc = -F _c d = – μ _k N d = – μ _k wd = – μ _k mgd

W _nc = -(0.2)(2)(10)(s)

W _nc = – (4)(2)

Hōʻike ka hōʻailona minus ua kūʻē ke kuhikuhi o ka ikaika friction kinetic i ke kuhikuhi o ka neʻe ʻana.

Ka loli o ka ikehu kinetic:

ΔEK = ½ m (v _t ² – v _o ² ) = ½ (2)(0 – 10 ² ) = 0 – 100 = -100

Ka nui o ka neʻe ʻana:

W _nc = ΔEK

– 4 kekona = – 100

s = -100/-4

s = 25 m

ʻAʻole maopopo

2. Heʻe iho kahi poloka ma luna o kahi mokulele hilig. ʻO ke koina o ka friction kinetic he 0.4. ʻO ka wikiwiki ma muli o ke koʻikoʻi he g = 10 ms ^-2 . E hoʻoholo i ka wikiwiki hope loa ke paʻi ka poloka i ka honua.

ʻIke ʻia:

Ke kiʻekiʻe mua (h _o ) = 6 m

Ke kiʻekiʻe hope loa (h _t ) = 0 m

Ka wikiwiki mua (v _o ) = 0

ʻO ke koina o ka friction kinetic ( _μk ) = 0.4

Ka wikiwiki ma muli o ke koʻikoʻi (g) = 10 ms ^-2

cos θ = 8/10

ʻO ka ʻāpana kū pololei o ke kaumaha = w _y = w cos θ = mg cos θ = m (10) (8/10) = m (10)(4/5) = m (40/5) = 8 m

Ikaika maʻamau = N = w _y = 8 m

Ka ikaika o ka paʻi kinetic = f _k = μ _k N = μ _k w _y = (0.4)(8 m) = 3.2 m

Makemake ʻia: Ka wikiwiki hope loa ( _vt )

Lōlā:

ʻO ke kumumanaʻo hana-ikehu mechanical:

W _nc = Δ EM

W _nc = Δ EK + Δ EP

Ka loli o ka ikehu kinetic:

ΔEK = 1/2 m (v_t² - v_o²) = 1/2 m (v_t² - 0) = 1/2 mv_t²

Ka loli o ka ikehu hiki:

Δ EP = mg (h _t – h _o ) = m (10)(0-6) = m (10)(-6) = – 60 m

Nā hana i hana ʻia e ka ikaika o ka friction kinetic:

W _nc = – f _k s = – ( 3.2 m)(10) = – 32 m

Hōʻike ka hōʻailona minus e kūʻē ana ke kuhikuhi o ka ikaika o ka friction kinetic i ke kuhikuhi o ka neʻe ʻana.

ʻO ka wikiwiki hope loa (vt ₎ :

W _nc = Δ EK + Δ EP

– 32 m = 1/2 mv _t ² – 60 m

– 32 m = m (1/2 v _t ² – 60)

– 32 = 1/2 v _t ² – 60

– 32 + 60 = 1/2 v _t ²

28 = 1/2 v _t ²

2 (28) = v _t ²

56 = v _t ²

vt = √4.14_​

vt ₌ 2 √14 ms ^-1

ʻAʻole maopopo

3. Heʻe iho kahi poloka ma luna o kahi mokulele hilig ʻino. ʻO ka wikiwiki mua he 0 m/s a ʻo ka wikiwiki hope loa he 10 ms ^-1 . Inā ʻo ka ikaika o ka friction kinetic he 2 N a me ka wikiwiki ma muli o ke umekaumaha g = 10 ms ^-2 , he aha ke kiʻekiʻe (h)?

ʻIke ʻia:

Nuipaʻa (m) = 1 kg

Ka wikiwiki mua (v _o ) = 0 (hoʻomaha poloka)

Ka wikiwiki hope loa (vt ₎ = 10 ms ^-1

Ke kiʻekiʻe mua (h _o ) = h

Kiʻekiʻe hope loa (h _t ) = 0

Ka ikaika o ka haʻalulu kinetic (f _k ) = 2 N

Ka wikiwiki ma muli o ke koʻikoʻi (g) = 10 ms ^-2

Makemake ʻia: Kiʻekiʻe (h)

Lōlā:

Ka hana i hana ʻia e ka ikaika o ka friction kinetic:

W _nc = – f _k s = – (2 )(15) = – 30

Hōʻike ka hōʻailona minus e kūʻē ana ke kuhikuhi o ka ikaika o ka friction kinetic i ke kuhikuhi o ka neʻe ʻana.

Ka loli o ka ikehu kinetic:

ΔEK = 1/2 m (v_t² - v_o²) = 1/2 (1)(10² - 0) = 1/2 (10²) = 1/2 (100) = 50

Ka loli o ka ikehu hiki:

Δ EP = mg (h _t – h _o ) = (1)(10)(0-h) = (10)(-h) = -10 h

ʻO ke kumumanaʻo hana-ikehu mechanical:

W _nc = Δ EK + Δ EP

– 30 = 50 – 10 hola

10 h = 50 + 30

10 hola = 80

h = 80/10

h = 8 mika

4Inā neʻe kahi poloka i lalo i kahi mokulele hiō ʻole, a laila….
A. ʻOi aku ka nui o ka hana i hana ʻia e ka ikaika umekaumaha ma luna o ka poloka ma mua o ka loli o ka ikehu hiki o ka poloka
B. Hoʻonui ka ikehu mechanical
C. Ua hoʻemi ʻia ka nui o ka ikehu kinetic a me kona ikehu hiki
D. Hana ʻia ka hana e ka ikaika friction e like me ka loli o ka ikehu kinetic o ka poloka
pāʻoihana

Ua hewa ʻo A

ʻO ka hana i hana ʻia e ka mana o ke koʻikoʻi ma luna o ka poloka ua like ia me ka loli o ka ikehu hiki ke koʻikoʻi o kahi poloka.

Ua hewa ʻo B

Inā laumania ka mokulele i kaha ʻia ma ke ʻano c a laila paʻa ka ikehu mechanical o ka poloka. I ka wā ma luna o ka mokulele inclined a ʻaʻole i neʻe, ua like ka ikehu mechanical o ka poloka me ka ikehu hiki ke umekaumaha. Ke hoʻomaha nei ka poloka no laila ʻaʻohe kona ikehu kinetic. Ke neʻe nei i lalo i kahi mokulele inclined, ua hoʻemi ʻia ke kiʻekiʻe o ka poloka no laila ua hoʻemi ʻia ka ikehu hiki ke umekaumaha. Ua emi ka ikehu hiki ke umekaumaha no ka mea ua loli ia i ka ikehu kinetic. ʻOiai ua loli ka ikehu hiki ke umekaumaha i ka ikehu kinetic, ua paʻa ka ikehu mechanical.

Inā ʻinoʻino ka mokulele inclined a laila ua emi ka ikehu mechanical o ka poloka ma muli o ka hana maikaʻi ʻole i hana ʻia e ka ikaika friction. He ikaika non-conservative ka ikaika friction. ʻO ka hana i hana ʻia e kahi ikaika non-conservative ma kahi mea e hoʻemi ai i ka ikehu mechanical o ka mea.

Pololei ʻo C

He ʻinoʻino ka mokulele inclined no laila aia kahi ikaika friction e hoʻokūkū ana i ka neʻe ʻana o ka poloka. He ikaika non-conservative ka ikaika friction. ʻŌlelo ka theorem work-mechanical e like ka hana i hana ʻia e kahi ikaika non-conservative (no ka laʻana ka ikaika friction) me ka loli o ka ikehu mechanical. I kēia alualu ʻana, ke emi nei ka ikehu mechanical.

ʻO ka ikehu mechanical o ka poloka = ka ikehu hiki ke umekaumaha + ka ikehu kinetic.

Ua hewa ʻo D.

ʻO ka hana i hana ʻia e ka ikaika friction ma ka poloka ua like ia me ka loli o ka ikehu mechanical o ka poloka, ʻaʻole ka loli o ka ikehu kinetic o ka poloka. ʻOiaʻiʻo e hoʻokūkū ka ikaika friction i ka neʻe ʻana o ka poloka no laila e hoʻemi ana i ka wikiwiki o ka poloka a hoʻemi i ka ikehu kinetic o ka poloka. Akā e hoʻomaopopo i ka ikehu kinetic o ka poloka mai ka ikehu hiki ke umekaumaha. No laila, he ʻoiaʻiʻo ka ʻōlelo ʻia ua hana ʻia ka hana e ka ikaika friction e like me ka loli o ka ikehu mechanical (emi ka ikehu mechanical).

ʻO ka pane pololei ʻo C.

5. Ua pā ʻia kahi mea ma luna o ka papahele ʻinoʻino no laila neʻe ia no 3 kekona a laila kū. Inā he 10 grams ka nuipaʻa i ʻike ʻia o ka mea, ʻo ka ikaika friction ma waena o ka mea a me ka papahele he 2 kilodyne. E hoʻoholo i ka hana i hana ʻia e ka ikaika friction.

A. 0.18 J

B. -0.18 J

C. 0.36 J

D. -0.36 J

ʻIke ʻia:

Ka manawa (t) = 3 kekona

Ka wikiwiki hope loa (vt ₎ = 0 m/s (hoʻomaha ka mea)

Ka nuipa o ka mea (m) = 10 grams = 10/1000 kg = 1/100 kg = 0.01 kg

ʻO ka ikaika paʻi (F) = 2 kilodynes = 2 x 10 ³ dynes

Makemake ʻia: Hana (W) i hana ʻia e ka ikaika friction

Lōlā:

Hoʻololi ʻana o nā anakahi o ka ikaika:

1 Newton = 1 x 10 ⁵ dyne

1 dyne = 1 / 10 ⁵ Newtons = 1 x 10 ^-5 Newtons = 10 ^-5 Newtons

Ka ikaika kuʻi (F) = 2 x 10 ³ dyne = 2 x 10 ³ x 10 ^-5 Newton = 2 x 10 ^-2 Newton = 2/100 Newton = 0.02 Newton

ʻŌlelo ka theorem work-mechanical i hana ʻia ka hana e ka ikaika non-conservative ma kahi mea e like me ka loli o ka ikehu mechanical o ka mea.

Inā neʻe kahi mea ma ka mokulele inclined a laila ʻo ka ikehu mechanical (ME) = ka ikehu hiki ke umekaumaha (PE) + ka ikehu kinetic (KE). Akā inā neʻe ka mea ma kahi mokulele ākea wale nō no laila ʻaʻohe loli o ke kiʻekiʻe ʻo ka ikehu mechanical = ka ikehu kinetic. Ma ka mokulele ākea, ʻo ka ikehu hiki ke umekaumaha he ʻole no ka mea ʻaʻohe loli o ke kiʻekiʻe.

He ikaika kūpaʻa ʻole ka ikaika friction. Hoʻemi pinepine ka ikaika friction i ka wikiwiki o ka mea a me ka ikehu kinetic o kahi mea. Hiki ke hoʻoholo ʻia ua like ka hana i hana ʻia e ka ikaika friction ma kahi mea me ka emi ʻana o ka ikehu mechanical.

Ma ke ʻano makemakika:

Hana (W) = Ka loli o ka ikehu mechanical (ΔEM)

Fs = ΔEP + ΔEK

ʻO Fs = mg Δh + ½ m ( _vt ² – _vo ² )

Fs = mg (0) + ½ m (0 ² – v _o ² )

Fs = 0 + ½ m (– (v _o ² ))

Fs = – ½ mv _o ² ———— Kaulike 1

Wehewehe: F = ikaika kuʻi, d = neʻe ʻana, m = nuipa, v ₌ wikiwiki mua

ʻAʻole ʻike ʻia ka neʻe ʻana (d) a me ka wikiwiki mua (v _{o ) no ka mea e helu mua iā v o} a i ʻole d. ʻO ka hana i hana ʻia e ka ikaika friction i helu ʻia me ka hoʻohana ʻana i kekahi o nā hoohalike ma hope o ka ʻike ʻia ʻana o v _o a i ʻole d.

ʻO ke kaulike o ka neʻe ʻana (d) ma ka neʻe laina ʻaʻole like:

vt ₂ = v _o ² + 2 (-a) ^s

ʻO ka wikiwiki hope loa (vt ₎ = 0 a ua kau inoa ʻia ka wikiwiki (a) he maikaʻi ʻole no ka mea ua hoʻēmi ʻia ka wikiwiki o ka mea (ua hoʻemi ʻia ka wikiwiki o ka mea).

0 = v_o² – 2 mau hoʻolaha

v_o² = 2 hoʻolaha

d = v _o ² / 2 a ———— Kaulike 2

E hoʻololi iā d ma ka hoohalike 2 me d ma ka hoohalike 1:

F d = – ½ mv _o ²

F (v _o ² /2a) = – ½ mv _o ²

(F/2a) v _o ² = – ½ mv _o ²

F/2a = – ½ m

F = (2)(a)(-1/2)(m)

F = – (a)(m)

a = – (F / m)

a = – 0.02 Newtons / 0.01 kilokani

a = – 2 Newton/kilokala

a = – 2 m/s ²

ʻO ke kaulike e helu ai i ka wikiwiki mua (v _o ) ma ka neʻe laina ʻole:

vt = v _o + ma —–> Ka wikiwiki hope loa (v _t ) = 0, Ka wikiwiki (a) = 2 m/s ₂ ^, ka manawa mamao (t) = 3 kekona

0 = v _o + (-2)(3)

0 = v _o – 6

v _o = 6 mika/kekona

Hana (W) i hana ʻia e ka ikaika friction:

W = – ½ mv _o ² = -1/2 (0.01)(6 ² ) = -1/2 (0.01)(36)

W = -1/2 (0.36)

W = – 0.18 Joule

ʻO ka hana i hana ʻia e ka ikaika friction ua hōʻailona ʻia he maikaʻi ʻole ʻo ia hoʻi e hoʻemi ana ka hana i ka ikehu mechanical o ka mea.

Inā ʻike ʻia ʻo d hiki ke helu ʻia ka hana me ka hoʻohana ʻana i ka hoohalike o W = F d.

ʻO ka pane pololei ʻo B.

[wpdm_package id='1178′]

1. Nā pilikia hana i hana ʻia e ka ikaika a me nā hoʻonā
2. Nā pilikia a me nā hoʻonā o ka ikehu hana-kinetic
3. Nā pilikia a me nā hoʻonā i nā kumumanaʻo ikehu hana-mekanika
4. Nā pilikia ikehu hiki ke umekaumaha a me nā hoʻonā
5. ʻO ka ikehu hiki ke loaʻa i nā pilikia a me nā hoʻonā o ka pūnāwai elastic
6. Nā pilikia mana a me nā hoʻonā
7. Ka hoʻohana ʻana i ka mālama ʻana i ka ikehu mechanical no ka neʻe hāʻule manuahi
8. Ka hoʻohana ʻana i ka mālama ʻana i ka ikehu mechanical no ka neʻe ʻana i luna a i lalo i ka neʻe hāʻule manuahi
9. Ka hoʻohana ʻana i ka mālama ʻana i ka ikehu mechanical no ka neʻe ʻana ma luna o kahi ʻili kūlou
10. Ka hoʻohana ʻana i ka mālama ʻana i ka ikehu mechanical no ka neʻe ʻana ma kahi mokulele inclined
11. Ka hoʻohana ʻana i ka mālama ʻana i ka ikehu mechanical no ka neʻe ʻana o ka projectile

heluhelu hou

Ikehu Hana-Kinetic :

1. Ua hoʻolalelale ʻia kahi kaʻa 5000-kg mai ka hoʻomaha a i 20 m/s. E hoʻoholo i ka hana upena i hana ʻia ma ke kaʻa.

ʻIke ʻia:

Nuipaʻa (m) = 5000 kg

Ka wikiwiki mua (v _o ) = 0 m/s ( kahi hoʻomaha kaʻa )

Ka wikiwiki hope loa (vt ₎ = 20 m/s

Makemake ʻia : pūnaewele

Lōlā:

ʻO ke kumumanaʻo o ka ikehu hana-kinetic :

_ʻupena W = Δ EK

W _upena = ½ m (v _t ² – v _o ² )

_ʻupena W = hana ʻupena

Δ EK = ka loli o ka ikehu kinetic

m = ka nuipaʻa (kg),

vt = ka wikiwiki hope loa (m/s) _,

v _o = ka wikiwiki mua (m/s).

Pūnaewele:

W _upena = ½ m (v _t ² – v _o ² )

W _upena = ½ (5000)(20 ² – 0 ² )

_ʻUpena W = (2500)(400 – 0)

_ʻupena W = (2500)(400)

_ʻupena W = 1000,000 Joule

ʻAʻole maopopo

2. Ua hoʻolalelale ʻia kahi mea he 10-kg mai 5 m/s a i 10 m/s. E hoʻoholo i ka hana upena i hana ʻia ma luna o ka mea!

ʻIke ʻia:

Nuipaʻa (m) = 10 kg

Ka wikiwiki mua (v _o ) = 5 m/s

Ka wikiwiki hope loa (vt ₎ = 10 m/s

Makemake ʻia : pūnaewele

Lōlā:

Pūnaewele:

_ʻupena W = Δ EK

W _upena = ½ m (v _t ² – v _o ² )

W _upena = ½ (10)(10 ² – 5 ² )

_ʻUpena W = (5)(100 – 25)

_ʻupena W = (5)(75)

_ʻupena W = 375 Joule

3. Hoʻoemi ka wikiwiki o kahi kaʻa 2000-kg mai 10 m/s a i 5 m/s. He aha ka hana i hana ʻia ma ke kaʻa?

ʻIke ʻia:

Ka nuipa o ke kaʻa (m) = 2000 kg

Ka wikiwiki mua (v _o ) = 10 m/s

Ka wikiwiki hope loa (vt ₎ = 5 m/s

Makemake ʻia: pūnaewele

Lōlā:

Pūnaewele:

_ʻupena W = Δ EK

W _upena = ½ m (v _t ² – v _o ² )

W _upena = ½ (2000)(5 ² – 10 ² )

_ʻUpena W = (1000)(25 – 100)

_ʻupena W = (1000)(-75)

_ʻupena W = -75,000 Joule

Hōʻike ka hōʻailona hua ʻole ua kūʻē ke kuhikuhi o ka neʻe ʻana i ke kuhikuhi o ka ikaika ʻupena.

4. He ikaika mau 60-N i hoʻokau ʻia ma luna o kahi mea 10-kg no 12 kekona. ʻO ka wikiwiki mua o kahi mea he 6 m/s a ua like ke kuhikuhi o ka mea me ke kuhikuhi o ka ikaika.

(1) ʻO ka hana i hana ʻia ma ka mea he 30,240 Joules

(2) ʻO ka ikehu kinetic hope loa he 30,240 joules

(3) ʻO ka mana he 2,520 Watt

(4) ʻO ka piʻi ʻana o ka ikehu kinetic o ka mea he 180 Joules

ʻO nā ʻōlelo kūpono…

ʻIke ʻia:

Ikaika (F) = 60 N

Ka manawa (t) = 12 kekona

Ka nuipa o ka mea (m) = 10 kg

Ka wikiwiki mua (v _o ) = 6 m/s

Makemake ʻia: Nā ʻōlelo kūpono

Lōlā:

Ka wikiwiki o ka mea:

∑F = ma

60 = 10 a

a = 60 / 10 = 6 m/s ²

ʻO ka wikiwiki hope loa:

vt = v _o + _ma

vt = 6 + ₍ 6)(12)

vt = 6 + ₇₂

vt = 78 m/ _s

ʻO ka mamao i hele ʻia i loko o 12 kekona:

s = v _o t + 1/2 ma ²

s = (6)(12) + 1/2 (6)(12) ²

s = 72 + (3)(144)

s = 72 + 432

s = 504 mika

(1) Hana i hana ʻia me ka ikaika

W = Fs = (60)(504) = 30,240 Joules

(2) ʻO ka ikehu kinetic hope loa

KE = 1/2 mv _t ² = 1/2 (10)(78) ² = (5)(6084) = 30,420 Joule

(3) Mana

P = W / t = 30,240 / 12 = 2,520 Joules/kekona

(4) Ka hoʻonui ʻia ʻana o ka ikehu kinetic

ΔKE = 1/2 mv _t ² – 1/2 mv _o ² = 1/2 m (v _t ² – v _o ² ) = 1/2 (10)(78 ² – 6 ² ) = 5 (6084 –36) = 5 (6048)

ʻΔKE = 30,240 Joule

ʻAʻole maopopo

5. Hana ʻia ka hana nui e ka helu mea…

Lōlā:

Hana ʻupena = loli o ka ikehu kinetic

W _upena = ½ m (v _t ² – v _o ² )

ʻO ka hana nui:

W ₁ = ½ (8)(4 ² – 2 ² ) = (4)(16 – 4) = (4)(12) = 48 Joules

W ₂ = ½ (8)(5 ² –3 ² ) = (4)(25 – 9) = (4)(16) = 64 Joules

W ₃ = ½ (10)(6 ² – 5 ² ) = (5)(36 – 25) = (5)(11) = 55 Joules

W ₄ = ½ (10)(4 ² – 0 ² ) = (5)(16 – 0) = (5)(16) = 80 Joules

W ₅ = ½ (20)(3 ² – 3 ² ) = (10)(9 – 9) = (10)(0) = 0 Joules

6. Ke holo nei kahi kaʻa 4000-kg ma kahi laina pololei ma 25 m/s. Ua hoʻēmi ʻia ke kaʻa i hiki ai i ka wikiwiki hope loa o ke kaʻa he 15 m/s. He aha ka hana i hana ʻia ma ke kaʻa.

ʻIke ʻia:

Nuipaʻa (m) = 4000 kg

ʻO ka wikiwiki mua (v _o ) = 25 m/s

ʻO ka wikiwiki hope loa (vt ₎ = 15 m/s

Makemake ʻia : Hana i hana ʻia ma ke kaʻa

Lōlā:

_ʻUpena W = ½ m (v _t ² – v _o ² ) = ½(4000)(15 ² -25 ² ) = (2000)(225-625) = (2000)(-400) = -800,000 Joules = -800 kJ

ʻAʻole maopopo

7. He 0.1-kg i hoʻolei ʻia ma ka ʻaoʻao pālahalaha ma 6 m/s mai ke kiʻekiʻe o 5 mika. Inā he 10 m/s ^{2 ka} wikiwiki o ka umekaumaha , a laila he aha ka ikehu kinetic o ka pōpō ma ke kiʻekiʻe o 2 mika.

ʻIke ʻia:

Nuipaʻa (m) = 0.1 kg

ʻO ka loli o ke kiʻekiʻe (h) = 5 m – 2 m = 3 mika

Ka wikiwiki ma muli o ke koʻikoʻi (g) = 10 m/s ²

Makemake ʻia: Ka ikehu kinetic ma ke kiʻekiʻe o 2 mika.

Lōlā:

Hiki ke hoʻomaopopo ʻia ka neʻe ʻana o ka projectile ma ke kālailai ʻana i nā ʻāpana moe a me ke kū pololei o ka neʻe ʻana. Ua kālailai ʻia ka neʻe ʻana ma ke kuhikuhi moe ma ke ʻano he neʻe wikiwiki mau a me ka neʻe ʻana ma ke kuhikuhi kū pololei ma ke ʻano he neʻe hāʻule manuahi a i ʻole ka neʻe kū pololei.

ʻO ka ikehu mechanical mua = ka ikehu hiki ke umekaumaha.

PE = mgh = (0.1)(10)(3) = 3 Joules.

ʻO ka ikehu mechanical hope loa = ka ikehu kinetic.

KE = 3 Joule.

8. Hoʻolalelale kahi kaʻa 1000-kg mai ka hoʻomaha a holo ma 5 m/s. He aha ka hana i hana ʻia e ke kaʻa?

ʻIke ʻia:

Nuipaʻa (m) = 1000 kg

Ka wikiwiki mua (v _o ) = 0

Ka wikiwiki hope loa (vt ₎ = 5 m/s

Makemake ʻia: Hana (W) i hana ʻia e ke kaʻa

Lōlā:

W _upena = ½ m (v _t ² – v _o ² )

Nā hana i hana ʻia e ke kaʻa:

_ʻUpena W = ½ (1000)(5 ² – 0 ² ) = (500)(25 – 0) = (500)(25) = 12,500 Joules

ʻAʻole maopopo

9. Ua kiola ʻia kahi pōpō 500-kalama i luna mai ka ʻili o ka honua me ka wikiwiki mua o 10 m/s² ^. ʻO ka wikiwiki ma muli o ke koʻikoʻi he 10 ms ^-2 . He aha ka hana i hana ʻia e ka ikaika kaumaha ke hiki ka pōpō i ke kiʻekiʻe loa.

ʻIke ʻia :

Ka nuipa o ka pōpō (m) = 500 grams = 0.5 kg

Ka wikiwiki mua (v _o ) = 10 m/s ²

Ka wikiwiki hope loa (vt ₎ = 0 (ka wikiwiki ma ke kiko kiʻekiʻe loa)

Ka wikiwiki ma muli o ke koʻikoʻi (g) = 10 m/s ²

Makemake ʻia: Hana (W) ma ke kaumaha

Lōlā:

ʻO ka hana upena i hana ʻia e ka ikaika upena ma luna o kahi mea = ka loli o ka ikehu kinetic.

_ʻupena W = ΔEK = EK _t – EK _o

Wnet = ½ mv _t ² – ½ mv _o ² = ½ m (v _t ² – v _o ² )

KE _t = ka ikehu kinetic hope loa, KE _o = ka ikehu kinetic mua, m = ka nuipa o ka mea, v _t = ka wikiwiki hope loa o ka mea, v _o = ka wikiwiki mua o ka mea.

Pūnaewele:

W _upena = ½ m (v _t ² – v _o ² ) = ½ (0.5)(0 ² – 10 ² )

_ʻUpena W = (0.25)(-100) = -25 Joules

Hōʻike ka hōʻailona Minus ua kūʻē ke kuhikuhi o ka neʻe ʻana i ke kaumaha o ka pōpō. Kū pololei ke kuhikuhi o ka pōpō a pololei ke kuhikuhi o ke kaumaha.

10. Hāʻule manuahi kahi mea 1-kg me ka ʻokoʻa kiʻekiʻe = 2.5 mika. ʻO ka wikiwiki ma muli o ke koʻikoʻi he 10 ms ^-2 . He aha ka hana i hana ʻia ma luna o ka mea?

ʻIke ʻia:

Ka nuipa o ka pōpō (m) = 1 kg

Ka wikiwiki mua (v _o ) = 0 m/s

Kiʻekiʻe (h) = 2.5 mika

Ka wikiwiki ma muli o ke koʻikoʻi (g) = 10 m/s ²

Makemake ʻia: Hana ʻupena i ka wā o ka neʻe ʻana

Lōlā:

Ka wikiwiki hope loa o ka pōpō ( _vt )

Ua helu ʻia me ka hoʻohana ʻana i ka hoohalike o ka neʻe hāʻule manuahi. ʻIke ʻia: Ka wikiwiki ma muli o ke koʻikoʻi (g) = 10 m/s ² , ʻO ka loli o ke kiʻekiʻe o ka pōpō (h) = 2.5 mika. Makemake ʻia: Ka wikiwiki hope loa.

vt _{2 =} ² gh = 2(10)(2.5) = 2(25)

vt ₌ √2(25)

vt ₌ 5√2

Hana ʻupena = ka loli o ka ikehu kinetic

W _upena = ΔEK = ½ m (v _t ² – v _o ² ) = ½ (1){(5√2) ² – 0 ² }

_ʻUpena W = ½ (25)(2) = 25 Joule

ʻAʻole maopopo

11. Hele kahi mea 2-kg ma 72 km/hola. Ma hope o ka hele ʻana i 400 mika, ʻo ka wikiwiki hope loa o ka mea he 144 km/hola. ʻO ka wikiwiki ma muli o ke koʻikoʻi he 10 ms ^-2 . E huli i ka hana upena.

ʻIke ʻia:

Ka nuipa o ka mea (m) = 2 kg

Ka wikiwiki mua (v _o ) = 72 km/hola = 20 m/s

Ka wikiwiki hope loa (vt ₎ = 144 km/h = 40 m/s

Ka mamao (s) = 400 mika

Ka wikiwiki ma muli o ke koʻikoʻi (g) = 10 m/s ²

Makemake ʻia: ʻO ka pūnaewele

Lōlā:

ʻO ka hana pūnaewele = nā loli o ka ikehu kinetic

W _upena = ΔEK = ½ m (v _t ² – v _o ² ) = ½ (2)(40 ² – 20 ² }

_ʻUpena W = ½ (2)(1600 – 400) = 1200 Joules

12. Hele kahi mea 2-kg ma 2 ms ^–1 . ʻO ka hana i hana ʻia ma luna o ka mea he 21 Joules. He aha ka wikiwiki hope loa o ka mea.

ʻIke ʻia:

Nuipaʻa (m) = 2 kg

Ka wikiwiki mua (v _o ) = 2 m/s

Hana (W) = 21 Joule

Makemake ʻia: ka wikiwiki hope loa ( _vt )

Lōlā:

_ʻupena W = ΔEK

W _upena = 1/2 mv _t ² -1/2 mv _o ²

W _upena = 1/2 m (v _t ² – v _o ² )

21 = 1/2 (2) (v _t ² – 2 ² )

21 = (v _t ² – 2 ² )

21 = v _t ² – 4

v _t ² = 21 + 4 = 25

vt ₌ √25

vt = 5 m/ _s

ʻAʻole maopopo

1 3 . Hana ka ikaika mau 8 N ma luna o kahi mea me ke kaumaha o 16 kg. Inā hoʻomaha mua ka mea, a laila e hoʻoholo i ka wikiwiki o ka mea ma hope o ka hana ʻana o ka ikaika ma luna o ka mea no 4 kekona.

ʻIke ʻia:

Ikaika mau (F) = 8 Newton

Ka nuipa o ka mea (m) = 16 kg

Ka wikiwiki mua o ka mea (v _o ) = 0 m/s

Hana ka ikaika o ka manawa ma luna o ka mea (t) = 4 kekona

Makemake ʻia: ʻO ka wikiwiki hope loa ( _vt )

Lōlā:

Hana = Ka loli o ka ikehu kinetic

W = KE hope loa – KE mua

W = ½ mv _t ² – ½ mv _o ²

W = ½ mv _t ² – 0

W = ½ mv _t ² —— Kaulike 1

Hana = Ikaika x Neʻe ʻana

W = F d

W = 8 lā

E hoʻohana i ka hoohalike o ka neʻe laina ʻole ma lalo nei e helu i ka neʻe ʻana (d):

d = v _o t + ½ ma ²

d = ka neʻe ʻana, v ₌ ka wikiwiki mua, t = ka wā manawa, a = ka wikiwiki

d = 0 + ½ ma ² = ½ ma ² —-> a = (v _t – v _o ) / t = v _t / t

d = ½ (v _t / t) t ²

^d = ½ (v _t ) t

E hoʻololi i ka neʻe ʻana (d) ma ka hoohalike o E hana me ka neʻe ʻana (d) ma kēia hoohalike:

W = 8 lā

W = 8(1/2)(vt ₎ (t)

W = (4)(v _t )(t) —— kaulike 2

Kaulike 1 = Kaulike 2

W = W

½ mv _t ² = (4)(v _t )(t)

½ mv _t = (4)(t)

½ (16)(v _t ) = 4(4)

8 v _t = 16

vt ₌ 16 / 8

v _t = 2 mika/kekona

14. No ka hoʻonui ʻana i ka wikiwiki o kahi mea i 2 manawa o ka wikiwiki mua, e hoʻoholo i ka hana e pono ai i ke kaʻina hana…

ʻIke ʻia:

Ka nuipa o ka mea (m) = 1 kg

Ka wikiwiki mua (v _o ) = 1 m/s

Ka wikiwiki hope loa (vt ₎ = 2 x ka wikiwiki mua = 2 x 1 = 2 m/s

Makemake ʻia: Hana

Lōlā:

ʻO ka ikehu kinetic mua:

KE kumu = ½ mv _o ² = ½ (1)(1) ² = ½ (1)(1) = ½ (1) = 0.5

ʻO ka ikehu kinetic hope loa ke lilo ka wikiwiki o ka mea i 2 manawa o kona wikiwiki mua:

I ka hopena = ½ mv _t ² = ½ (1)(2) ² = ½ (4) = 2

ʻO ke kumumanaʻo o ka ikehu hana-kinetic:

Hana = Ka loli o ka ikehu kinetic

Hana = Ka ikehu kinetic hope loa - ka ikehu kinetic mua

Hana = 2 – 0.5

Hana = 1.5

ʻO ka ikehu kinetic mua = 0.5

Hana = 3 x 0.5 = 1.5

ʻO ka hana e pono ai he 3 manawa o kona ikehu kinetic mua.

15. Neʻe kekahi kaʻa me ke kaumaha o 1500 kg me ka wikiwiki o 36 km/hola ma ke alanui laina a laumania. Ua hoʻolalelale ʻia ke kaʻa i 72 km/hola. E hoʻoholo i ka hana e pono ai e hoʻolalelale i ke kaʻa.

ʻIke ʻia:

Ka nuipa o ke kaʻa (m) = 1500 kg

Ka wikiwiki mua o ke kaʻa (v _o ) = 36 km/hola = 36,000 mika / 3600 kekona = 10 mika/kekona

Ka wikiwiki hope loa o ke kaʻa (vt ₎ = 72 km/hola = 72,000 mika / 3600 kekona = 20 mika/kekona

Makemake ʻia: Hana e pono ai e hoʻolalelale i ke kaʻa

Lōlā:

ʻO ke kumumanaʻo o ka ikehu hana-kinetic:

W = EK hope loa - EK mua

W = ½ mv _t ² – ½ mv _o ² = ½ m (v _t ² –v _o ² )

W = ½ (1500)(20 ² – 10 ² )

W = ½ (1500)(400 – 100)

W = ½ (1500)(300)

W = (1500)(150)

W = 225,000 Joules

16. Neʻe mua kahi mea me ke kaumaha o 2 kg i ka wikiwiki o 72 km/hola ^-1 . Ma hope o ka neʻe ʻana ma ke alanui pololei a hiki i 400 m, ʻo ka wikiwiki o ka mea he 144 km/hola ^-1 . E hoʻoholo i ka hana holoʻokoʻa ma luna o ka mea.

ʻIke ʻia:

Ka nuipa o ka mea (m) = 2 kg

Ka wikiwiki mua (v _o ) = 72 km/hola = 72,000 mika / 3600 kekona = 20 m/s

Ka wikiwiki hope loa (vt ₎ = 144 km/hola = 144,000 mika / 3600 kekona = 40 m/s

Ka neʻe ʻana o ka mea = 400 mika

Makemake ʻia: Hana ʻupena ma ka mea

Lōlā:

ʻŌlelo ke kumumanaʻo o ka ikehu hana-kinetic e hana ka hana upena ma kahi mea e like me ka loli o ka ikehu kinetic o ka mea.

ʻupena W = TO hope loa - TO mua

W upena = ½ mv _t ² – ½ mv _o ²

W upena = ½ m (v _t ² – v _o ² )

W upena = ½ (2)(40 ² – 20 ² )

ʻupena W = 1600 – 400

ʻupena W = 1200 Joule

Hō'ike:

W = Hana, KE = ikehu kinetic

ʻO ka ikehu kinetic

17. He pōkā 10-gram e neʻe ana ma ka wikiwiki mau o 100 m/s. He aha ka ikehu kinetic o ka pōkā.

ʻIke ʻia:

Ka nuipa o ka pōkā (m) = 10 grams = 10/1000 kilokani = 1/100 kilokani = 0.01 kilokani

Ka wikiwiki o ka pōkā (v) = 100 mika/kekona

Makemake ʻia: Ikehu kinetic

Lōlā:

KE = 1/2 mv ²

KE = 1/2 (0,01 kg)(100 m/s) ²

KE = 1/2 (0,01 kg)(10.000 m ² / s ² )

KE = (0,01 kg)(5000 m ² / s ² )

KE = 50 kg ^m² / ^s²

KE = 50 Joule

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1. Nā pilikia hana i hana ʻia e ka ikaika a me nā hoʻonā
2. Nā pilikia a me nā hoʻonā o ka ikehu hana-kinetic
3. Nā pilikia a me nā hoʻonā i nā kumumanaʻo ikehu hana-mekanika
4. Nā pilikia ikehu hiki ke umekaumaha a me nā hoʻonā
5. Ka ikehu hiki ke loaʻa o nā pilikia a me nā hoʻonā o ka pūnāwai elastic
6. Nā pilikia mana a me nā hoʻonā
7. Ka hoʻohana ʻana i ka mālama ʻana i ka ikehu mechanical no ka neʻe hāʻule manuahi
8. Ka hoʻohana ʻana i ka mālama ʻana i ka ikehu mechanical no ka neʻe ʻana i luna a i lalo i ka neʻe hāʻule manuahi
9. Ka hoʻohana ʻana i ka mālama ʻana i ka ikehu mechanical no ka neʻe ʻana ma kahi ʻili piʻo
10. Ka hoʻohana ʻana i ka mālama ʻana i ka ikehu mechanical no ka neʻe ʻana ma kahi mokulele inclined
11. Ka hoʻohana ʻana i ka mālama ʻana i ka ikehu mechanical no ka neʻe ʻana o ka projectile

heluhelu hou

1. Huki kekahi kanaka i kahi poloka 2 m ma kahi ʻili ākea ma ka ikaika mau F = 20 N. E hoʻoholo i ka hana i hana ʻia e ka ikaika F e hana ana ma luna o ka poloka.

ʻIke ʻia:

Ikaika (F) = 20 N

Ka neʻe ʻana (s) = 2 m

Kihi (θ ) = 0

Makemake ʻia : Hana (W)

Lōlā:

W = F d cos θ = (20)(2)(cos 0) = (20)(2)(1) = 40 Joule

ʻAʻole maopopo

2. He ikaika F = 10 N e hana ana ma kahi pahu 1 m ma kahi ʻili ākea. Hana ka ikaika ma kahi kihi 30 ^o e like me ka mea i hōʻike ʻia ma ke kiʻi ma lalo. E hoʻoholo i ka hana i hana ʻia e ka ikaika F!

ʻIke ʻia :

Ikaika (F) = 10 N

ʻO ka ikaika pae (F _x ) = F cos 30 ^o = (10)(0.5√3) = 5√3 N

Ka neʻe ʻana (d) = 1 mika

Makemake ʻia : Hana (W)?

Hoʻonā :

W = F _x d = (5√3)(1) = 5√3 Joules

3. Hāʻule kūʻokoʻa ke kino mai ka hoʻomaha ʻana, mai ke kiʻekiʻe o 2 m. Inā he 10 m/s ² ka wikiwiki ma muli o ke koʻikoʻi , e hoʻoholo i ka hana i hana ʻia e ka ikaika o ke koʻikoʻi!

ʻIke ʻia:

Ka nuipa o ka mea (m) = 1 kg

Kiʻekiʻe (h) = 2 m

Ka wikiwiki ma muli o ke koʻikoʻi (g) = 10 m/s ²

Makemake ʻia: Hana i hana ʻia e ka ikaika o ke koʻikoʻi (W)

Lōlā:

W = F d = wh = mgh

W = (1)(10)(2) = 20 Joule

W = hana, F = ikaika, d = mamao, w = kaumaha , h = kiʻekiʻe, m = nuipa, g = wikiwiki ma muli o ke kaumaha.

ʻAʻole maopopo

4. Hoʻopili ʻia kahi mea 1-kg i kahi pūnāwai a laila ua hoʻolōʻihi ʻia he 2 cm. Inā ʻo ka wikiwiki ma muli o ke kaumaha he 10 m/s ² , e hoʻoholo (a) ke kūpaʻa pūnāwai (b) ka hana i hana ʻia e ka ikaika pūnāwai ma luna o ka mea

ʻIke ʻia:

Nuipaʻa (m) = 1 kg

Ka wikiwiki ma muli o ke koʻikoʻi (g) = 10 m/s ²

Hoʻolōʻihi (x) = 2 kenimika = 0.02 m

Kaumaha (w) = mg = (1 kg)(10 m/s ² ) = 10 kg m/s ² = 10 N

Makemake ʻia: Ke kūpaʻa o ka puna a me ka hana i hana ʻia e ka ikaika puna

Lōlā:

(a) Paʻa mau o ka pūnāwai

ʻO ke ʻano o ke kānāwai o Hooke :

F = k-x.

k = F / x = w / x = mg / x

k = (1)(10) / 0.02 = 10 / 0.02

k = 500 N/m

(b) ka hana i hana ʻia e ka ikaika puna

W = – ½ kx ²

W = – ½ (500)(0.02) ²

W = – (250)(0.0004)

W = -0.1 Joule

Hōʻike ka hōʻailona hua ʻole i ke kuhikuhi o ka ikaika puna e kūʻē ana i ke kuhikuhi o ka neʻe ʻana o ka mea.

ʻAʻole maopopo

5. Hoʻolalelale ka ikaika F = 10 N i kahi pahu ma luna o kahi neʻe ʻana he 2 m. He ʻoʻoleʻa ka papahele a hoʻopuka i ka ikaika kuʻi F _k = 2 N. E hoʻoholo i ka hana upena i hana ʻia ma luna o ka pahu.

ʻIke ʻia:

Ikaika (F) = 10 N

Ka ikaika o ka haʻalulu kinetic (F _k ) = 2 N

Ka neʻe ʻana (d) = 2 m

Makemake ʻia: Pūnaewele (W _net )

Lōlā:

Ka hana i hana ʻia e ka ikaika F:

W ₁ = F d cos 0 = (10)(2)(1) = 20 Joules

Hana i hana ʻia e ka ikaika o ka friction kinetic (Fk ₎ :

W ₂ = F _k d = (2)(2)(cos 180) = (2)(2)(-1) = -4 Joules

Pūnaewele:

_ʻupena W = W ₁ – W ₂

_ʻupena W = 20 – 4

_ʻupena W = 16 Joule

6. He aha ka hana i hana ʻia e ka ikaika F ma ka poloka.

ʻIke ʻia:

Ikaika (F) = 12 Newton

Ka neʻe ʻana (d) = 4 mika

Makemake ʻia: Hana (W)

Lōlā:

W = F d = (12 Newton)(4 mika) = 48 N m = 48 Joules

ʻAʻole maopopo

7. Ua paʻi ʻia kahi poloka e ka ikaika o 200 N. ʻO ka neʻe ʻana o ka poloka he 2 mika. He aha ka hana i hana ʻia ma ka poloka?

ʻIke ʻia:

Ikaika (F) = 200 Newton

Ka neʻe ʻana (d) = 2 mika

Makemake ʻia: Hana (W)

Lōlā:

Hana:

W = Fs

W = (200 Newton) (2 mika)

W = 400 N m

W = 400 Joule

8. Makemake ka mea hoʻokele o ke kaʻa sedan e hoʻokū i kāna kaʻa ma kahi o 0.5 m ma mua o ke kalaka aia ma 10 m mai ke kūlana o ke kaʻa sedan. He aha ka hana e pono ai no ke kaʻa sedan?

ʻIke ʻia:

Ka neʻe ʻana (d) = 10 mika – 0.5 mika = 9.5 mika

Ikaika (F) = 50 Newton

Makemake ʻia: Hana (W)

Lōlā:

W = Fs

W = (50 Newton) (9.5 mika)

W = 475 N m

W = 475 Joule

ʻAʻole maopopo

9.

ʻO ka hana i hana ʻia e Tom lāua ʻo Jerry i hiki ai i ke kaʻa ke neʻe a hiki i 4 mika. ʻO nā ikaika i hoʻopuka ʻia e Tom lāua ʻo Jerry he 50 N a me 70 N.

ʻIke ʻia:

Ka neʻe ʻana (s) = 4 mika

Ka ikaika ʻupena (F) = 50 Newtons + 70 Newtons = 120 Newtons

Makemake ʻia: Hana (W)

Lōlā:

W = Fs = (120 Newton)(4 mika) = 480 N m = 480 Joules

10. Huki kekahi mea hoʻokele i kahi kaʻa i neʻe ai ke kaʻa a hiki i 1000 cm. He aha ka hana i hana ʻia ma ke kaʻa?

ʻIke ʻia:

Ikaika (F) = 250 Newton

Ka neʻe ʻana (s) = 1000 kenimika = 1000/100 mika = 10 mika

Makemake ʻia: Hana (W)

Lōlā:

W = Fs = (250 Newton)(10 mika) = 2500 N m = 2500 Joules

11. Ma muli o ke kiʻi ma lalo nei, inā he 375 Joules ka hana i hana ʻia e ka ikaika upena, e hoʻoholo i ka neʻe ʻana o ka mea.

ʻIke ʻia:

Hana (W) = 375 Joule

Ka ikaika ʻupena ( ΣF) = 40 N + 10 N – 25 N = 25 Newtons ( ma ka ʻākau )

Makemake ʻia: Ka hoʻoneʻe ʻana ( d )

Lōlā:

ʻO ke kaulike o ka hana:

W = Fs

Ka neʻe ʻana o ka mea:

d = W / F = 375 Joules / 25 Newtons

d = 15 mika s

12. ʻO nā hana ma lalo nei ʻaʻole hana ...

A. E hoʻokuke i kahi mea a hiki i 10 mika

B. E paʻi i kahi kaʻa a hiki i kona neʻe ʻana

C. E paʻi i kahi pā

D. Huki i kahi pahu

Lōlā:

ʻO ke kaulike o ka hana:

W = ΣF s

W = hana , F = ikaika , d = neʻe ʻana

Ma muli o ke ʻano hana i luna, hana ʻia ka hana ma ka ikaika a aia kahi neʻe ʻana.

ʻO ka pane pololei ʻo C.

1 3 . Paʻi ʻo Andrew i kahi mea me ka ikaika o 20 N no laila neʻe ka mea i ka neʻe pōʻai me ka radius o 7 mika. E hoʻoholo i ka hana i hana ʻia e Andrew no ʻelua manawa o ka neʻe pōʻai.

A. 0 Joule

B. 1400 Joule

C. 1540 Joule

D. 1760 Joule

Lōlā:

Inā e paʻi ke kanaka i ka noho huila no ʻelua manawa o ka neʻe pōʻai ʻana, a laila hoʻi ke kanaka a me ka noho huila i ke kūlana mua, no laila he ʻole ka neʻe ʻana o ke kanaka.

Ka neʻe ʻana = 0 no laila hana = 0.

ʻO ka pane pololei ʻo A.

14. Pahu kekahi i kahi mea ma ka papahele me ka ikaika o 350 N. Hoʻopuka ka papahele i ka ikaika friction o 70 N. E hoʻoholo i ka hana i hana ʻia e ka ikaika e hoʻoneʻe i ka mea a hiki i 6 mika.

A. 45 J

B. 72 J

C. 1680 J

D. 2580 J

ʻIke ʻia:

ʻO ka ikaika o ka paʻi (F) = 350 Newtons

Ka ikaika kuʻi (F _fric ) = 70 Newtons

Ka neʻe ʻana o ka mea (s) = 6 mika

Makemake ʻia: Hana (W)

Lōlā:

ʻElua mau mana e hana ana ma luna o ka mea, ka mana hoʻoneʻe (F) a me ka mana kuʻi (F _fric ). Ua like ke kuhikuhi o ka mana hoʻoneʻe me ka neʻe ʻana o ka mea no ka mea hana ka mana hoʻoneʻe i kahi hana maikaʻi. Ma kekahi ʻaoʻao, aia ke kuhikuhi ʻē aʻe o ka mana kuʻi me ka neʻe ʻana o ka mea i hana ai ka mana kuʻi i kahi hana maikaʻi ʻole.

Ka hana i hana ʻia e ka ikaika hoʻouka:

W = F d = (350 Newton)(6 mika) = 2100 Newton-mika = 2100 Joules

Nā hana i hana ʻia e ka ikaika friction:

W = – (F _fric )(s) = – (70 Newton)(6 mika) = – 420 Newton-mika = – 420 Joules

ʻO ka pūnaewele:

ʻUpena W = 2100 Joules – 420 Joules

ʻupena W = 1680 Joule

ʻO ka pane pololei ʻo C.

15. Ua paʻi ʻia kahi mea e ka ikaika pālahalaha o 14 Newtons ma luna o kahi papahele ʻinoʻino me ka ikaika kuʻi o 10 Newtons. E hoʻoholo i ka hana upena o ka hoʻoneʻe ʻana i ka mea a hiki i 8 mika.

A. 0.5 Joule

B. 3 Joule

C. 32 Joule

D. 192 Joule

ʻIke ʻia:

Ka ikaika paʻi (F) = 14 Newton

Ka ikaika kuʻi (F _fric ) = 10 Newtons

Ka neʻe ʻana o ka mea (d) = 8 mika

Makemake ʻia: Hana (W)

Lōlā:

ʻElua mau mana e hana ana ma luna o kahi mea, ʻo ia ka mana paʻi (F) a me ka mana kuʻi (F _fric ).

Ua like ke kuhikuhi o ka ikaika paʻi me ka neʻe ʻana o ka mea i hana ai ka ikaika paʻi i kahi hana maikaʻi. Ma kekahi ʻaoʻao, ua kūʻē ke kuhikuhi o ka ikaika kuʻi me ka neʻe ʻana o ka mea i hana ai ka ikaika kuʻi i kahi hana maikaʻi ʻole.

Ka hana i hana ʻia e ka ikaika hoʻouka:

W = Fs = (14 Newton)(8 mika) = 112 Newton mika = 112 Joules

Nā hana i hana ʻia e ka ikaika friction:

W = – (F _fric )(s) = – (10 Newton)(8 mika) = – 80 Newton mika = – 80 Joules

ʻO ka pūnaewele:

ʻUpena W = 112 Joules – 80 Joules

ʻupena W = 32 Joule

ʻO ka pane pololei ʻo C.

16. E hoʻoholo i ka hana ʻupena ma muli o ke kiʻi ma lalo nei.

A. 360 Joule

B. 450 Joule

C. 600 Joule

D. 750 Joule

Lōlā:

Hana = Ikaika (F) x neʻe ʻana (d)

Hana = ʻĀpana o ka huinakolu 1 + ʻāpana o ka huinahā + ʻāpana o ka huinakolu 2

Work = 1/2(40-0)(3-0) + (40-0)(9-3) + 1/2(40-0)(12-9)

Hana = 1/2(40)(3) + (40)(6) + 1/2(40)(3)

Hana = (20)(3) + 240 + (20)(3)

Hana = 60 + 240 + 60

Hana = 360 Joule

ʻO ka pane pololei ʻo A.

17. Ua hoʻopaʻa pololei ʻia kahi ʻāpana lāʻau me ka lōʻihi o 60 cm i ka lepo. Ua hahau ʻia ka lāʻau me ka hāmare 10-kg mai ke kiʻekiʻe o 40 cm ma luna o ka piko o ka lāʻau. Inā ʻo ka ikaika kū'ē awelika o ka honua he 2 x 103 N ^a ʻo ka wikiwiki ma muli o ke koʻikoʻi he 10 m/s2 ^, a laila e komo piha ka lāʻau i loko o ka lepo ma hope o…. nā kuʻi.

H. 4

B. 16

C. 28

D. 30

ʻIke ʻia:

Ka nuipa o ka hāmare (m) = 10 kg

^{Ka wikiwiki ma muli o ke koʻikoʻi (} g) = 10 m/ s2

Kaumaha o ka hāmare (w) = mg = (10)(10) = 100 kg m/s ²

Ka neʻe ʻana o ka hāmare ma mua o ke kuʻi ʻana i ka lāʻau (d) = 40 kenimika = 0.4 mika

ʻO ke kū'ē o ka lāʻau (F) = 2 x 10 ³ N = 2000 N

Ka lōʻihi o ka lāʻau (s) = 60 kenimika = 0.6 mika

Makemake ʻia: E komo piha ka wahie i loko o ka lepo ma hope o…. kuʻi.

Lōlā:

ʻO ka hana i hana ʻia ma ka hāmare ke neʻe ka hāmare a hiki i 0.4 mika penei:

W = F d = ws = (100 N)(0.4 m) = 40 Nm = 40 Joules

Ka hana i hana ʻia e ka ikaika kū'ē o ka honua:

W = F d = (2000 N)(0.6 m) = 1200 Nm = 1200 Joules

E komo piha ka wahie i loko o ka lepo ma hope o .... kuʻi.

1200 Joules / 40 Joules = 30

ʻO D ka pane pololei.

[wpdm_package id='1192′]

1. Nā pilikia hana i hana ʻia e ka ikaika a me nā hoʻonā
2. Nā pilikia a me nā hoʻonā o ka ikehu hana-kinetic
3. Nā pilikia a me nā hoʻonā i nā kumumanaʻo ikehu hana-mekanika
4. Nā pilikia ikehu hiki ke umekaumaha a me nā hoʻonā
5. ʻO ka ikehu hiki ke loaʻa i nā pilikia a me nā hoʻonā o ka pūnāwai elastic
6. Nā pilikia mana a me nā hoʻonā
7. Ka hoʻohana ʻana i ka mālama ʻana i ka ikehu mechanical no ka neʻe hāʻule manuahi
8. Ka hoʻohana ʻana i ka mālama ʻana i ka ikehu mechanical no ka neʻe ʻana i luna a i lalo i ka neʻe hāʻule manuahi
9. Ka hoʻohana ʻana i ka mālama ʻana i ka ikehu mechanical no ka neʻe ʻana ma kahi ʻili piʻo
10. Ka hoʻohana ʻana i ka mālama ʻana i ka ikehu mechanical no ka neʻe ʻana ma kahi mokulele inclined
11. Ka hoʻohana ʻana i ka mālama ʻana i ka ikehu mechanical no ka neʻe ʻana o ka projectile

heluhelu hou

1. ʻO ka mamao o ka Honua mai ka Lā he 149.6 x 106 ^km a ʻo ka manawa o ka hoʻohuli ʻana o ka Honua he 1 makahiki. E helu iā T ² / r ³

ʻIke ʻia:

T = 1 makahiki, r = 149.6 x 10 ⁶ km

Makemake ʻia : T ² / r ³ = … ?

Hoʻonā :

k = T² /r³ = 1² / (149.6 x 10⁶)³ = 1 / (3348071.9 x 10¹⁸) = 2.98 x 10^-25 makahiki²/ km³

ʻAʻole maopopo

2. ^ʻO ke kūpaʻa honua (G) = 6.67 x 10 ^-11 Nm² /kg² ^a me 1.99 x ^10⁻¹30 kg ko ka Lā.

ʻAʻole maopopo

3. ʻO ka mamao awelika o ka Honua mai ka Lā he 149.6 x 10 ⁶ km a ʻo ka mamao awelika o Mercury mai ka Lā he 57.9 x 10 ⁶ km. ʻO ka manawa o ka hoʻohuli ʻana o ka Honua he 1 makahiki, he aha ka manawa o ka hoʻohuli ʻana o Mercury?

ʻIke ʻia:

r o ka Honua = 149.6 x 10 ⁶ km

r o ka mercury = 57.9 x 10 ⁶ km

T o ka Honua = 1 makahiki

Makemake ʻia: T o ka mercury?

Lōlā:

[wpdm_package id='953′]

1. Nā pilikia a me nā hoʻonā o ke kānāwai o Newton no ka umekaumaha honua
2. Nā mana umekaumaha, nā pilikia kaumaha, a me nā hoʻonā
3. Ka wikiwiki ma muli o nā pilikia umekaumaha a me nā hoʻonā
4. Nā pilikia a me nā hoʻonā o ka satelite Geosynchronous
5. Nā pilikia a me nā hoʻonā o ke kānāwai o Kepler nā pilikia a me nā hoʻonā

heluhelu hou

1. He aha ke kiʻekiʻe o kahi ukali geosynchronous ma luna o ka ʻili o ka Honua?

G = ke kūpaʻa honua = 6.67 x 10 ^-11 N ^m² / ^kg²

M = ke kaumaha o ka Honua = 5.97 x ¹⁰²⁴ kg

T = 24 hola = 24 (3600 kekona) = 86,400 kekona = 8.64 x 10 ⁴ kekona

pāʻoihana

ʻO ke kiʻekiʻe o ka ukali ma luna o ka ʻili o ka Honua = 4.22 x 10 ⁷ m = 4.22 x 10 ⁴ km = 42,200 km

ʻO ke kiʻekiʻe o ka ukali ma luna o ka ʻili o ka Honua = 6.38 x 10 ⁶ m = 6.38 x 10 ³ km = 6380 km

Ke kiʻekiʻe o ka ukali ma luna o ka ʻili o ka Honua = ka mamao o ka ukali mai ke kikowaena o ka Honua - ka radius o ka Honua

ʻO ke kiʻekiʻe o ka ukali ma luna o ka ʻili o ka Honua = 42,200 km – 6380 km

ʻO ke kiʻekiʻe o ka ukali ma luna o ka ʻili o ka Honua = 35,820 km

ʻAʻole maopopo

2. He aha ka wikiwiki o kahi satelite geosynchronous?

Paʻa mau honua (G) = 6.67 x 10 ^-11 N m ² /kg ²

Ka nuipa o ka Honua (m _E ) = 5.97 x 10 ²⁴ kg

ʻO ka mamao ma waena o ka satelite a me ke kikowaena o ka Honua (r) = 4.22 x ¹⁰⁷ m

pāʻoihana

a i ʻole e hoʻohana i kēia hoʻohālikelike

[wpdm_package id='949′]

1. Nā pilikia a me nā hoʻonā o ke kānāwai o Newton no ka umekaumaha honua
2. Nā mana umekaumaha, nā pilikia kaumaha, a me nā hoʻonā
3. Ka wikiwiki ma muli o nā pilikia umekaumaha a me nā hoʻonā
4. Nā pilikia a me nā hoʻonā o ka satelite Geosynchronous
5. Nā pilikia a me nā hoʻonā o ke kānāwai o Kepler nā pilikia a me nā hoʻonā

heluhelu hou

1. ʻO ka mamao ma waena o ke kanaka 40-kg a me ke kanaka 30-kg he 2 m. He aha ka nui o ka ikaika umekaumaha e hoʻokau ai kekahi i kekahi. ʻO ke kūpaʻa honua = 6.67 x 10 ^-11 N ^m² / ^kg²

ʻIke ʻia:

m ₁ = 40 kg, m ₂ = 30 kg, r = 2 m, G = 6.67 x 10 ^-11 N m ² / kg ²

Makemake ʻia: ka nui o ka ikaika umekaumaha (F)?

Lōlā:

ʻAʻole maopopo

2. ʻO ka mamao ma waena o ka Honua a me ka Mahina (r) he 3.84 x 108 ^m . He aha ka nui o ka ikaika umekaumaha e hoʻokau ai kekahi i kekahi?

ʻIke ʻia:

Ka nuipa o ka Honua (m _E ) = 5.97 x 10 ²⁴ kg

Ka nuipa o ka mahina (m _M ) = 7.35 x 10 ²² kg

ʻO ka mamao ma waena o ke kikowaena o ka Honua a me ke kikowaena o ka Mahina (r) = 3.84 x ¹⁰⁸ m

Paʻa mau honua (G) = 6.67 x 10 ^-11 N m ² / kg ²

Makemake ʻia: Ka nui o ka ikaika umekaumaha (F)

Lōlā:

ʻAʻole maopopo

3. He aha ka mamao mai ka Honua mai, ʻo ka nui o ka ikaika umekaumaha o ka honua a me ka mahina he ʻole?

ʻIke ʻia:

Ka nuipa o ka Honua = 5.97 x ¹⁰²⁴ kg

Ka nuipa o ka mahina = 7.35 x ¹⁰²² kg

ʻO ka mamao ma waena o ke kikowaena o ka Honua a me ke kikowaena o ka Mahina (r) = 3.84 x 108 ^m.

Paʻa mau honua ( G) = 6.67 x 10 ^-11 N ^m² / ^kg²

Makemake ʻia: mamao mai ka Honua

Lōlā:

ʻO ka ikaika umekaumaha upena he ʻole.

E hoʻohana i ke ʻano quadratic:

ʻA = – 6.35

B = – 7.68 x 10 ⁸

C = 87.76 x 10 ^-14

 

[wpdm_package id='955′]

1. Nā pilikia a me nā hoʻonā o ke kānāwai o Newton no ka umekaumaha honua
2. Nā mana umekaumaha, nā pilikia kaumaha, a me nā hoʻonā
3. Ka wikiwiki ma muli o nā pilikia umekaumaha a me nā hoʻonā
4. Nā pilikia a me nā hoʻonā o ka satelite Geosynchronous
5. Nā pilikia a me nā hoʻonā o ke kānāwai o Kepler nā pilikia a me nā hoʻonā

 

heluhelu hou