Laʻana o nā nīnau neʻe pololei

19 mau laʻana o nā nīnau neʻe pololei

1. E nānā i ka pakuhi o ka wikiwiki (v) e kūʻē i ka manawa (t) o kahi mea e neʻe ana ma kahi laina pololei. ʻO ka nui o ka deceleration i ʻike ʻia e ka mea….
A. 2,5 ms^-2
B. 3,5 ms^-2
C. 4,0 ms^-2
D. 5,0 ms^-2
E. 6,0 ms^-2
Pahana
AB = ka wikiwiki mau (neʻe laina e loli like ana), BC = ka wikiwiki mau (neʻe laina e loli like ana), CD = ka hoʻēmi mau (neʻe laina e loli like ana).

ʻO A ka pane pololei.

2. ʻO ke kiʻikuhi ma ka ʻaoʻao he kiʻikuhi ia o kahi mea e neʻe ana ma kahi laina pololei. ʻO ka mamao i hele ʻia e ka mea ma waena o 0 a me 8 kekona he….
A. 72 m
B. 64 m
C. 48 m
D. 24 m
E. 12 m
Pahana
E hoʻohana i ke ʻano hana like me ka pilikia ma mua, kahi i hele ai ka mamao = ka ʻāpana o ka ʻāpana i aka ʻia ma ka pakuhi. E nānā i ka pakuhi ma luna! Ua māhele ʻia ka ʻāpana i aka ʻia i mau ʻāpana i hiki ke helu ʻia ka ʻāpana me ka hoʻohana ʻana i ke ʻano hana i ʻike ʻia.
ʻĀpana o ka mokulele 1 = ʻāpana o ka huinakolu = ½ (4-0)(12-0) = ½ (4)(12) = (2)(12) = 24
ʻĀpana o ka mokulele 2 = ʻāpana o ka huinahā = (8-4)(12-0) = (4)(12) = 48

Ka mamao i hele ʻia i ka manawa o 8 kekona = 24 + 48 = 72 mika
ʻO A ka pane pololei.

3. E nānā i ke kiʻikuhi o ka wikiwiki v e kūʻē iā t no ka mea e neʻe ana ma kahi laina pololei!
ʻO ka mamao i hele ʻia i loko o 12 kekona he….
A. 8 m
B. 10 m
C. 12 m
D. 24 m
E. 36 m
Pahana
Ua like kēia nīnau me ka mea ma mua. ʻOiai ua nīnau ka nīnau ma mua no ka mamao i hele ʻia i loko o 10 kekona, ua nīnau kēia nīnau no ka mamao i hele ʻia i loko o 12 kekona.

4. Neʻe kekahi mea ma kahi laina pololei ma ka wikiwiki mau o 36 km/h ^-1 no 5 kekona, a laila hoʻolalelale i ka wikiwiki o 1 m/s ^-2 no 10 kekona a hoʻēmi i ka wikiwiki ma ka wikiwiki o 2 m/s ^-2 a hiki i ka wā e kū ai ka mea. ʻO ke kiʻi (vt) e hōʻike ana i ka huakaʻi a ka mea...

Pahana
Ua ʻike ʻia:
Neʻe 1 = GLB
Ka wikiwiki mau (v) = 36 km/h = 36 (1000 m) / 3600 s = 36.000 m / 3600 s = 10 m/s
Ka manawa (t) = 5 kekona
Neʻe 2 = GLBB i hoʻolalelale ʻia
Ka wikiwiki mua (v_o) = ka wikiwiki o ka neʻe ʻana 1 = 10 m/s
Hoʻolalelale (a) = 1 m/s2
Ka manawa (t) = 10 kekona
Neʻe 3 = GLBB i hoʻolohi ʻia
Ka wikiwiki (a) = -2 m/s²
Ka wikiwiki hope loa (v_t) = 0 m/s
Makemake ʻia: He kiʻikuhi e hōʻike ana i ka hele ʻana o kahi mea

Pane:
Hiki ke hoʻoholo ʻia ke kiʻi ma hope o ka ʻike ʻana i ka wikiwiki hope loa o ka neʻe ʻana 2 a me ka manawa no ka neʻe ʻana 3.
Ka wikiwiki hope loa o ka neʻe ʻana 2:
v_t = v_o + ma
v_t = 10 + (1)(10) = 10 + 10 = 20 m/s
Ka wikiwiki hope loa o ka neʻe ʻana 2 (v_t) = ka wikiwiki mua o ka neʻe ʻana 3 (v_o) = 20 m/s
Ka manawa o ka neʻe ʻana 3:
v_t = v_o + ma
0 = 20 + (-2)(t)
0 = 20 – 2t
20 = 2t
t = 20/2
t = 10 kekona

E nānā i ka pakuhi ma luna.
Neʻe 1: Neʻe ka mea i ka wikiwiki mau o 10 m/s no 5 kekona.
Neʻe 2: Hoʻolalelale ka mea no 10 kekona a hiki i kona wikiwiki i 20 m/s
Neʻe 3: Ua lohi ka mea no 10 kekona a hiki i kona kū ʻana.
ʻO ke kiʻikuhi kūpono ka kiʻikuhi ma ka pane B.
ʻO ka pane pololei ʻo B.

5. Neʻe mua kahi kaʻa ma kahi laina pololei ma ka wikiwiki mau o 5 ms ^-1 . Ma hope o ka mālama ʻana i kona wikiwiki no 10 s, hoʻolalelale ke kaʻa i hiki i loko o nā kekona 5 e hiki mai ana he hoʻolalelale o 1 ms ^-2 . A laila ua pio ka ʻenekini kaʻa i hiki ai i ke kaʻa ke kū ma hope o ka hele ʻana i kahi mamao holoʻokoʻa o 137,5 m. Hiki ke wehewehe ʻia ka neʻe ʻana o ke kaʻa e kahi kiʻi o ka wikiwiki (v) e kūʻē i ka manawa (t) i kūpono....

Pahana
Ua ʻike ʻia:
Neʻe 1 = GLB
Ka wikiwiki mau (v) = 5 m/s
Ka manawa (t) = 10 kekona
Neʻe 2 = GLBB i hoʻolalelale ʻia
Ka wikiwiki mua (v_o) = ka wikiwiki o ka neʻe ʻana 1 = 5 m/s
Hoʻolalelale (a) = 1 m/s2
Ka manawa (t) = 5 kekona
Neʻe 3 = GLBB i hoʻolohi ʻia
Ka wikiwiki hope loa (v_t) = 0 m/s
Ka huina o ka mamao i hele ʻia (s) = 137,5 m/s
Makemake ʻia: He kiʻikuhi e hōʻike ana i ka hele ʻana o kahi mea
Pane:
Ka mamao i hele ʻia e ka neʻe ʻana 1:
s = vt = (5)(10) = 50 mika
Ka mamao i hele ʻia e ka neʻe ʻana 2:
s = v_o t + ½ ma² = (5)(5) + ½ (1)(5)2 = 25 + ½ (25) = 25 + 12,5 = 37,5 mika
Ka mamao i hele ʻia e ka neʻe ʻana 3:
137,5 – (50 + 37,5) = 137,5 – 87,5 = 50 mika

Hiki ke hoʻoholo ʻia ke kiʻi ma hope o ka ʻike ʻana i ka wikiwiki hope loa o ka neʻe ʻana 2 a me ka manawa no ka neʻe ʻana 3.
Ka wikiwiki hope loa o ka neʻe ʻana 2
Ua helu ʻia ka wikiwiki hope loa o ka neʻe ʻana 2 me ka hoʻohana ʻana i ka ʻikepili o ka neʻe ʻana 2.
v_t = v_o + ma
v_t = 5 + (1)(5) = 5 + 5 = 10 m/s
Ka wikiwiki hope loa o ka neʻe ʻana 2 (v_t) = ka wikiwiki mua o ka neʻe ʻana 3 (v_o) = 10 m/s

Ka manawa o ka neʻe ʻana 3
Hiki ke helu ʻia ka manawa ma hope o ka ʻike ʻia ʻana o ka deceleration. Hoʻohana ka helu ʻana o ka deceleration (a) a me ka manawa (t) i ka ʻikepili neʻe 3.

Ka hoʻolohi ʻana o kahi mea e neʻe ana 3:
v_t² = v_o² + 2 mau ʻauamo
0² = 10² + 2 a (50)
0 = 100 + 100 a
100 = -100 a
a = – 100 / 100
a = – 1 m/s²
Ka manawa o ka neʻe ʻana 3:
v_t = vo + ma
0 = 10 + (-1) t
0 = 10 – t
t = 10 kekona
E nānā i ka pakuhi ma luna.
Neʻe 1: Neʻe ka mea i ka wikiwiki mau o 5 m/s no 10 kekona.
Neʻe 2: Hoʻolalelale ka mea no 5 kekona a hiki i kona wikiwiki i 10 m/s
Neʻe 3: Ua lohi ka mea no 10 kekona a hiki i kona kū ʻana.
ʻO D ka pane pololei.

6. Ke neʻe nei kahi kaʻa me ke kaumaha o 800 kg ma kahi laina pololei me ka wikiwiki mua o 36 km/h.^-1 Ma hope o ka hele ʻana i kahi mamao o 150 m, lilo ka wikiwiki i 72 km/h^-1ʻO ka manawa huakaʻi o ke kaʻa he…
A. 5 kekona
B. 10 kekona
C. 17 kekona
D. 25 kekona
E. 35 kekona
Pahana
Ua ʻike ʻia:
v_o = 36 km/h = 36000 m / 3600 s = 10 m/s
v_t = 72 km/h = 72000 m / 3600 s = 20 m/s
s = 150 mika
Nīnau ʻia: ka manawa huakaʻi (t)?
Pane:
ʻEkolu mau ʻano hana no ka neʻe laina wikiwiki like (GLBB):
v_t = v_o + ma
s = vo t + ½ ma²
v_t² = v_o² + 2 mau ʻauamo
Ma muli o ka ʻikepili i ʻike ʻia, ʻaʻole hiki iā mākou ke helu pololei i ka manawa huakaʻi me ka hoʻohana ʻana i kekahi o nā haʻilula ma luna.
E helu mua i ka wikiwiki (a) me ka hoʻohana ʻana i ke ʻano hana 3.
v_t² = v_o² + 2 mau ʻauamo
20² = 10² + 2 a (150)
400 = 100 + 300 a
400 – 100 = 300 a
300 = 300 a
a = 300 / 300
a = 1 m/s²
E helu i ka wā ma waena (t) me ka hoʻohana ʻana i ke ʻano hana mua.
v_t = v_o + ma
20 = 10 + (1) t
20 – 10 = t
t = 10 kekona
ʻO ka pane pololei ʻo B.

7. Ke holo nei kekahi mea hoʻokele kaʻa ma ka wikiwiki o 20 m/s. I kona ʻike ʻana i kahi puʻupuʻu wikiwiki i mua ona, ua hehi ʻo ia i nā paleki a kū ke kaʻa ma hope o 5 kekona. E helu i ka mamao i hele ʻia e ke kaʻa!
Pahana
Ua ʻike ʻia:
Ka wikiwiki mua (v_o) = 20 m/s
Ka wikiwiki hope loa (v_t) = 0 m/s
Ka manawa (t) = 5 kekona
Nīnau ʻia: ka mamao i hele ʻia
Pane:
E helu mua i ka wikiwiki o ke kaʻa:
v_t = v_o + ma
0 = 20 + a 5
-20 = 5a
a = -20/5
a = -4 m/s²
E helu i ka mamao i hele ʻia e ke kaʻa:
s = v_o t + 1/2 ma²
s = (20)(5) + 1/2 (-4)(5)2 = (20)(5) + (-2)(25)
s = 100 – 50
s = 50 mika
ʻO ka mamao i hele ʻia e ke kaʻa he 50 mika.

8. E nānā i ke kiʻi ma lalo nei.

ʻO ka mamao i hele ʻia e ka mea i ka manawa t = 40 kekona…

A. 100 m

B. 160 m

C. 220 m

D. 280 m

E. 320 m

Pahana

ʻĀpana o ke kahua 1 = ʻāpana o ka huinahā = (20-0)(8-0) = (20)(8) = 160 mika

ʻĀpana o ka mokulele 2 = ʻāpana o ka huinakolu = ½ (25-20)(8-0) = ½ (5)(8) = (5)(4) = 20 mika

ʻĀpana o ka mokulele 3 = ʻāpana o ka huinakolu = ½ (30-25)(8-0) = ½ (5)(8) = (5)(4) = 20 mika

ʻĀpana o ke kahua 4 = ʻāpana o ka huinahā = (40-30)(8-0) = (10)(8) = 80 mika

Ka mamao i hele ʻia i loko o kahi manawa he 40 kekona = 160 + 20 + 20 + 80 = 280 mika

ʻO D ka pane pololei.

9. Ua hōʻike ʻia ka loli o ka wikiwiki o kahi mea e neʻe ana no 20 kekona ma ka pakuhi vt ma lalo!

ʻO ka mamao i hele ʻia e kahi mea i ka wā e neʻe ana he…

A. 200 m

B. 260 m

C. 300 m

D. 400 m

E. 470 m

Pahana

ʻĀpana o ka mokulele 1 = ʻāpana o ka huinakolu = ½ (5-0)(20-0) = ½ (5)(20) = (5)(10) = 50 mika

ʻĀpana o ke kahua 2 = ʻāpana o ka huinahā = (15-5)(20-0) = (10)(20) = 200 mika

ʻĀpana o ka mokulele 3 = ʻāpana o ka huinakolu = ½ (20-15)(20-0) = ½ (5)(20) = (5)(10) = 50 mika

Ka mamao i hele ʻia i loko o kahi manawa he 20 kekona = 50 + 200 + 50 = 300 mika

ʻO C ka pane pololei.

10. Neʻe kekahi mea ma kahi laina pololei ma ka wikiwiki mau o 36 km/h ^-1 no 5 kekona, a laila hoʻolalelale i ka wikiwiki o 1 m/s ^-2 no 10 kekona a hoʻēmi i ka wikiwiki ma ka wikiwiki o 2 m/s ^-2 a hiki i ka wā e kū ai ka mea. ʻO ke kiʻi (vt) e hōʻike ana i ka huakaʻi a ka mea...

Pahana

Ua ʻike ʻia:
Neʻe 1 = GLB
Ka wikiwiki mau (v) = 36 km/h = 36 (1000 m) / 3600 s = 36.000 m / 3600 s = 10 m/s
Ka manawa (t) = 5 kekona
Neʻe 2 = GLBB i hoʻolalelale ʻia
Ka wikiwiki mua (v_o) = ka wikiwiki o ka neʻe ʻana 1 = 10 m/s
Hoʻolalelale (a) = 1 m/s²
Ka manawa (t) = 10 kekona
Neʻe 3 = GLBB i hoʻolohi ʻia
Ka wikiwiki (a) = -2 m/s²
Ka wikiwiki hope loa (v_t) = 0 m/s
Makemake ʻia: He kiʻikuhi e hōʻike ana i ka hele ʻana o kahi mea
Pane:

Hiki ke hoʻoholo ʻia ke kiʻi ma hope o ka ʻike ʻana i ka wikiwiki hope loa o ka neʻe ʻana 2 a me ka manawa no ka neʻe ʻana 3.
Ka wikiwiki hope loa o ka neʻe ʻana 2:
v_t = v_o + ma
v_t = 10 + (1)(10) = 10 + 10 = 20 m/s

Ka wikiwiki hope loa o ka neʻe ʻana 2 (v_t) = ka wikiwiki mua o ka neʻe ʻana 3 (v_o) = 20 m/s
Ka manawa o ka neʻe ʻana 3:
v_t = v_o + ma
0 = 20 + (-2)(t)
0 = 20 – 2t
20 = 2t
t = 20/2
t = 10 kekona

E nānā i ka pakuhi ma luna.
Neʻe 1: Neʻe ka mea i ka wikiwiki mau o 10 m/s no 5 kekona.
Neʻe 2: Hoʻolalelale ka mea no 10 kekona a hiki i kona wikiwiki i 20 m/s
Neʻe 3: Ua lohi ka mea no 10 kekona a hiki i kona kū ʻana.
ʻO ke kiʻikuhi kūpono ka kiʻikuhi ma ka pane B.
ʻO ka pane pololei ʻo B.

11. Neʻe mua kahi kaʻa ma kahi laina pololei ma ka wikiwiki mau o 5 ms ^-1 . Ma hope o ka mālama ʻana i kona wikiwiki no 10 s, hoʻolalelale ke kaʻa i hiki i loko o nā kekona 5 e hiki mai ana he hoʻolalelale o 1 ms ^-2 . A laila ua pio ka ʻenekini kaʻa i hiki ai i ke kaʻa ke kū ma hope o ka hele ʻana i kahi mamao holoʻokoʻa o 137,5 m. Hiki ke wehewehe ʻia ka neʻe ʻana o ke kaʻa e kahi kiʻi o ka wikiwiki (v) e kūʻē i ka manawa (t) i kūpono....

Pahana
Ua ʻike ʻia:
Neʻe 1 = GLB
Ka wikiwiki mau (v) = 5 m/s
Ka manawa (t) = 10 kekona
Neʻe 2 = GLBB i hoʻolalelale ʻia
Ka wikiwiki mua (v_o) = ka wikiwiki o ka neʻe ʻana 1 = 5 m/s
Hoʻolalelale (a) = 1 m/s²
Ka manawa (t) = 5 kekona
Neʻe 3 = GLBB i hoʻolohi ʻia
Ka wikiwiki hope loa (v_t) = 0 m/s

Ka huina o ka mamao i hele ʻia (s) = 137,5 m/s
Makemake ʻia: He kiʻikuhi e hōʻike ana i ka hele ʻana o kahi mea
Pane:
Ka mamao i hele ʻia e ka neʻe ʻana 1:
s = vt = (5)(10) = 50 mika
Ka mamao i hele ʻia e ka neʻe ʻana 2:
s = v_o t + ½ ma² = (5)(5) + ½ (1)(5)² = 25 + ½ (25) = 25 + 12,5 = 37,5 mika
Ka mamao i hele ʻia e ka neʻe ʻana 3:
137,5 – (50 + 37,5) = 137,5 – 87,5 = 50 mika

Hiki ke hoʻoholo ʻia ke kiʻi ma hope o ka ʻike ʻana i ka wikiwiki hope loa o ka neʻe ʻana 2 a me ka manawa no ka neʻe ʻana 3.
Ka wikiwiki hope loa o ka neʻe ʻana 2
Ua helu ʻia ka wikiwiki hope loa o ka neʻe ʻana 2 me ka hoʻohana ʻana i ka ʻikepili o ka neʻe ʻana 2.

vt = v _o + _ma

v _t = 5 + (1)(5) = 5 + 5 = 10 m/s

Ka wikiwiki hope loa o ka neʻe ʻana 2 (vt ₎ = ka wikiwiki mua o ka neʻe ʻana 3 (vO ₎ = 10 m/s

Ka manawa o ka neʻe ʻana 3

Hiki ke helu ʻia ka manawa ma hope o ka ʻike ʻia ʻana o ka deceleration. Hoʻohana ka helu ʻana o ka deceleration (a) a me ka manawa (t) i ka ʻikepili neʻe 3.

Ka hoʻolohi ʻana o kahi mea e neʻe ana 3:

vt ₂ = v _o ^{2 +} 2 es

0 ² = 10 ² + 2 a (50)

0 = 100 + 100 a

100 = -100 a

a = – 100 / 100

a = – 1 m/s ²

Ka manawa o ka neʻe ʻana 3:

vt = v _o + _ma

0 = 10 + (-1) t

0 = 10 – t

t = 10 kekona

E nānā i ka pakuhi ma luna.

Neʻe 1: Neʻe ka mea i ka wikiwiki mau o 5 m/s no 10 kekona.

Neʻe 2: Hoʻolalelale ka mea no 5 kekona a hiki i kona wikiwiki i 10 m/s

Neʻe 3: Ua lohi ka mea no 10 kekona a hiki i kona kū ʻana.

ʻO D ka pane pololei.

Neʻe Pololei

12.

Hōʻike ka pakuhi ma ka ʻākau i kahi mea e neʻe ana ma kahi laina pololei. ʻO ka mamao i hele ʻia e ka mea ma waena o 0 a me 8 kekona he….

A. 72 m
B. 64 m
C. 48 m
D. 24 m
E. 12 m

Pahana
E hoʻohana i ke ʻano hana like me ka pilikia ma mua, kahi i hele ai ka mamao = ka ʻāpana o ka ʻāpana i aka ʻia ma ka pakuhi. E nānā i ka pakuhi ma luna! Ua māhele ʻia ka ʻāpana i aka ʻia i mau ʻāpana i hiki ke helu ʻia ka ʻāpana me ka hoʻohana ʻana i ke ʻano hana i ʻike ʻia.
ʻĀpana o ka mokulele 1 = ʻāpana o ka huinakolu = ½ (4-0)(12-0) = ½ (4)(12) = (2)(12) = 24
ʻĀpana o ka mokulele 2 = ʻāpana o ka huinahā = (8-4)(12-0) = (4)(12) = 48

Ka mamao i hele ʻia i ka manawa o 8 kekona = 24 + 48 = 72 mika
ʻO A ka pane pololei.

13.

E hoʻolohe i ka pakuhi ka wikiwiki ʻo v e kūʻē iā t no kahi mea e neʻe ana ma kahi laina pololei ma lalo!
ʻO ka mamao i hele ʻia i loko o 12 kekona he….

A. 8 m
B. 10 m
C. 12 m
D. 24 m
E. 36 m

Pahana
Ua like kēia nīnau me ka mea ma mua. ʻOiai ua nīnau ka nīnau ma mua no ka mamao i hele ʻia i loko o 10 kekona, ua nīnau kēia nīnau no ka mamao i hele ʻia i loko o 12 kekona.
ʻĀpana o 1 = ʻāpana o ka huinakolu = ½ (2-0)(4-0) = ½ (2)(4) = 4
ʻĀpana o ka mokulele 2 = ʻāpana o ka huinahā = (6-2)(4-0) = (4)(4) = 16
ʻĀpana o 3 = ʻāpana o ka huinakolu = ½ (8-6)(4-0) = ½ (2)(4) = 4
ʻĀpana o 4 = ʻāpana o ka huinakolu = ½ (10-8)(4-0) = ½ (2)(4) = 4
ʻĀpana o 5 = ʻāpana o ka huinahā = (12-10)(4-0) = (2)(4) = 8

Ka mamao i hele ʻia i loko o kahi manawa he 10 kekona = 4 + 16 + 4 + 4 + 8 = 36 mika
ʻO D ka pane pololei.

Puna nīnau:

Nā Nīnau Hoʻokolohua Lahui no ke Kino no ke Kula Kiʻekiʻe/Kula Kiʻekiʻe ʻOihana

Nā laʻana o nā nīnau neʻe pololei like
14. Neʻe kekahi kaʻa ma kahi laina pololei ma ka wikiwiki mau o 10 m/s. E hoʻoholo i ka mamao i hele ai ke kaʻa ma hope o ka neʻe ʻana no 10 m/s.
Pahana
ʻO ka wikiwiki mau o 10 mika/kekona, ʻo ia hoʻi, neʻe ke kaʻa i 10 mika i kēlā me kēia 1 kekona.
Ma hope o 2 kekona, neʻe ka mokokaikala i kahi mamao o (2)(10) = 20 mika,
Ma hope o 3 kekona, neʻe ka mokokaikala i kahi mamao o (3)(10) = 30 mika,
Ma hope o 10 kekona, neʻe ka mokokaikala i kahi mamao o (10)(10) = 100 mika.
E aʻo hou aʻe ma ka ʻaoʻao laʻana o ka neʻe pololei like

Laʻana o ka neʻe laina i hoʻolalelale ʻia like
15. Neʻe kahi mea i hoʻomaha mua me ka wikiwiki mau o 5 m/s.²E hoʻoholo i ka wikiwiki a me ka mamao i hele ʻia ma hope o 5 kekona.
Pahana
(a) Ka wikiwiki ma hope o 5 kekona
Ka wikiwiki mau o 5 m/s² ʻO ke ʻano kēia, piʻi ka wikiwiki ma 5 m/s i kēlā me kēia 1 kekona. Ma hope o 2 kekona, piʻi ka wikiwiki i 10 m/s. Ma hope o 5 kekona, piʻi ka wikiwiki i 25 m/s.
(b) Ka mamao i hele ʻia ma hope o 5 kekona
Ua ʻike ʻia:
Ka wikiwiki mua (v_o) = 0 (ua hoʻomaha mua ka mea).
Hoʻolalelale (a) = 5 m/s²
Ka manawa (t) = 5 kekona
Nīnau ʻia: ka mamao i hele ʻia
Pane:
s = v_o t + ½ ma² = (0)(5) + ½ (5)(5²) = 0 + (2,5)(25) = 62,5 mika
ʻO ka mamao i hele ʻia ma hope o 5 kekona he 62,5 mika.

16. Ke neʻe nei kahi kaʻa 400-kg ma kahi laina pololei ma ka wikiwiki mua o 72 km/h. Ma hope o ka holo ʻana i 100 mika, piʻi kona wikiwiki i 108 km/h. ʻO ka manawa i lawe ʻia e ke kaʻa e hele ai i kēia mamao he...
A. 1 kekona
B. 2 kekona
C. 3 kekona
D. 4 kekona
E. 5 kekona
Pahana
Ua ʻike ʻia:
v_o = 72 km/h = (72)(1000 m) / 3600 s = 20 m/s
v_t = 108 km/h = (108)(1000 m) / 3600 s = 30 m/s
s = 100 mika
Nīnau ʻia: ka manawa manawa (t)?
Pane:

17. Hōʻike ka pakuhi ma ka ʻaoʻao i ka neʻe ʻana o kahi kaʻa e neʻe ana ma kahi laina pololei ma kahi wikiwiki mau. ʻO ka mamao i hele ʻia e ke kaʻa i 8 kekona he...

A. 40 m
B. 60 m
C. 80 m
D. 100 m
E. 120 m
Pahana
Ua ʻike ʻia:
v_o = 10m/s
v_t = 20m/s
t = 8 kekona
Nīnau ʻia: Ka mamao i hele ʻia?
Pane:

ʻO ka pane pololei ʻo E.

18. ʻO ke kiʻikuhi ma ka ʻaoʻao he kiʻikuhi ia o kahi mea e neʻe ana ma kahi laina pololei. ʻO ka mamao i hele ʻia e ka mea ma waena o 0 a me 6 kekona he...

A. 40 mika
B. 45 m
C. 50 mika
D. 55 m
E. 60 m
Pahana
Ka mamao i hele ʻia = ka ʻāpana o ke kiʻi (s = vt)
Ka mamao i hele ʻia 1 = ½ (10)(3) = (5)(3) = 15 mika
Ka mamao i hele ʻia 2 = (10)(6-3) = (10)(3) = 30 mika
Ka huina o ka mamao i hele ʻia:
15 mika + 30 mika = 45 mika
ʻO ka pane pololei ʻo B

E aʻo hou aʻe ma ka ʻaoʻao laʻana no ka neʻe laina wikiwiki like.

Laʻana o ka neʻe hāʻule manuahi
19. Ua hāʻule ka mango mai ke kumu a hiki i ka honua ma hope o 2 kekona. ʻO ka wikiwiki o ka hua mango i kona pā ʻana i ka honua he... g = 10 m/s²
Pahana
Inā ʻo ka wikiwiki ma muli o ke koʻikoʻi = 10 m/s² No laila, ʻo ka mango a i ʻole kekahi mea e hāʻule manuahi ana e ʻike i ka piʻi ʻana o ka wikiwiki o 10 m/s i kēlā me kēia 1 kekona. Ma hope o 2 kekona, ʻo ka wikiwiki o ka mango he 20 m/s.
E aʻo hou aʻe ma ka ʻaoʻao laʻana o ka neʻe hāʻule manuahi