1. ʻO ka mamao ma waena o nā ʻauwaʻa ʻelua o nā nalu o ka ʻilikai he 20 m. Lana kahi mea ma luna o ka ʻilikai o ka wai i ʻike ai i ka neʻe haʻalulu. Inā he 4 kekona ka manawa e hele ai i hoʻokahi haʻalulu, a laila ʻo ka wikiwiki o ka nalu he …. m/s
H. 20
B. 15
C. 10
D. 5
ʻIke ʻia:
Ka lōʻihi o ka nalu (λ) = 20 mika
Ka wā (T) = 4 kekona
Makemake ʻia: Ka wikiwiki o ka nalu (v)
Lōlā:
ʻO ke kaulike o ka wikiwiki o nā nalu:
v = λ / T = 20 mika / 4 kekona = 5 mika / kekona
ʻO D ka pane pololei.
2. Aia ʻelua mau kiko A a me B ma ke kaula a he 90 kenimika ke kaʻawale kekahi i kekahi. Ma ke kaula e hoʻolaha ai nā nalu transverse , no laila aia ke kiko A ma ka piko o ka nalu, ke kiko B ma lalo o ka nalu, a ma waena o lākou, aia ʻelua mau piko a me ʻelua mau ʻauwai. Inā he 0.3 kekona ka manawa o ka nalu, a laila ʻo ka hoʻolaha ʻana o ka nalu…
A. 10.8 kenimika/kekona
B. 18.0 kenimika/kekona
C. 120.0 kenimika/s
D. 200.0 kenimika/kekona
ʻIke ʻia:
Ka mamao AB (l) = 90 kenimika
Ka wā o ka nalu (T) = 0.3 kekona
Alapine (frequency) o ka nalu (f) = 1/0.3 kekona
Aia ke kiko A ma ka piko o ka nalu a aia ke kiko B ma ke awāwa o ka nalu.
Ma waena o nā kiko A a me B, aia nā ʻaoʻao ʻelua a me nā ʻauwai ʻelua.
Makemake ʻia: Ka wikiwiki o ka nalu (v = f λ)
Lōlā:
Ma muli o ke kiʻi, hiki ke hoʻoholo he 2.5 mau nalu. Ka mamao o kahi nalu (λ) = 90 kenimika / 2.5 = 36 kenimika
Ka wikiwiki o ka nalu:
v = f λ = (1 / 0.3)(36) = 36 / 0.3 = 120 knm/s.
ʻO ka pane pololei ʻo C.
3. Hōʻike ka pakuhi ma lalo nei i ka neʻe ʻana o kahi kiko i loko o kekahi waena ma ke ʻano he hana o ka manawa ke hele kahi nalu ma waena o ka waena.
Inā he 6 mika ka lōʻihi o ka nalu, a laila ʻo ka wikiwiki o ka laha ʻana o ka nalu he…
A. 3 m/s
B. 6 m/s
C. 8 m/s
D. 12 m/s
ʻIke ʻia:
ʻElua mau nalu e pili ana i ka pakuhi ma luna.
Ka mamao o 1 nalu (λ) = 6 mika / 2 = 3 mika
Ka wā (T) = 0.5 kekona
Makemake ʻia: Ka wikiwiki o nā nalu (v)
Lōlā:
v = f λ = λ / T = 3 mika / 0.5 kekona = 6 mika / kekona
ʻO ka pane pololei ʻo B.
4. Ma muli o ke kiʻi ma lalo nei, ʻo ke kiko nona ka ʻokoʻa pae ¾ me ke kiko A ʻo ia ….
A. Kiko B
B. Kiko C
C. Kiko D
D. Kiko E
pāʻoihana
He ʻokoʻa pae ko ka kiko B o ¼ λ me ka kiko A
He ʻokoʻa pae ko ka kiko C he 2/4 λ a i ʻole 1/2 λ me ka kiko A.
He ʻokoʻa pae ko ka kiko D he 3/4 λ me ka kiko A
He ʻokoʻa pae ko ka kiko F he 5/4 λ me ka kiko A.
ʻO ka pane pololei ʻo C.
5. Ma luna o ka ʻili o ka loko, aia ʻelua lau maloʻo he 60 kenimika ka mamao mai kekahi i kekahi. Neʻe lāua i luna a i lalo e like me ka ʻili o ka wai me ka alapine (frequency) o 2 Hz. Ke kau kekahi lau ma ka piko, aia nā lau ʻē aʻe ma ke awāwa, a ma waena o lāua, aia kekahi piko a me kekahi awāwa. E hoʻoholo i ka wikiwiki o ka laha ʻana o ka nalu o ka nalu.
A. 20 kenimika/kekona
B. 30 kenimika/kekona
C. 80 kenimika/s
D. 120 kenimika/kekona
ʻIke ʻia:
Ka mamao ma waena o nā lau ʻelua = 60 kenimika
Alapine (f) = 2 Hz = 2
Makemake ʻia: Ka wikiwiki o ka nalu
Lōlā:
Ma waena o nā lau ʻelua, aia he 1.5 mau nalu. ʻO ka mamao o 1 nalu he (λ) = 60 kenimika / 1.5 = 40 kenimika
Ka wikiwiki o ka nalu (v):
v = f λ = (2 Hz)(40 kenimika) = 80 kenimika/kekona
ʻO ka pane pololei ʻo C.
6. Ma muli o ke kiʻi ma lalo nei, e hoʻoholo i ka amplitude, ka wā, ke alapine (frequency), a me ka wikiwiki o ka nalu.
Lōlā:
Ka nui (A) = 4 mika
Ka wā (T) = 6 kekona / 3 = 2 kekona
Alapine (f) = 1 / T = 1 / 2 = 0.5 hertz
Ka lōʻihi o ka nalu (λ) = 24 mika / 3 = 8 mika
Ka wikiwiki o ka nalu (v) = f λ = (0.5 hertz) (8 mika) = 4 mika/kekona a i ʻole
Ka wikiwiki o ka nalu (v) = λ / T = 8 mika / 2 kekona = 4 mika/kekona
ʻO D ka pane pololei.
7. Ma luna o ke kaula me ka lōʻihi o 1.2 m a me ke kaumaha o 200 g ua hoʻokumu ʻia he 1.5 mau nalu sinusoidal me ke alapine (frequency) o 50 Hz. Ma muli o kēia ʻikepili, e hoʻoholo i ka wā nalu a me ka ikaika ume o ke kaula.
A. Ka wā = 0.02 kekona a me ka ikaika hoʻoluhi = 6.67 N
B. Ka wā = 0.01 kekona a me ka ikaika hoʻoluhi = 6.67 N
C. Ka wā = 0.02 kekona a me ka ikaika hoʻoluhi = 266.67 N
D. Ka wā = 0.01 kekona a me ka ikaika hoʻoluhi = 266.67 N
ʻIke ʻia:
ʻO ka lōʻihi o ke kaula (l) = 1.2 mika a aia he 1.5 mau nalu sinusoidal no laila ʻo ka mamao o 1 nalu (λ) = 1.2 mika / 1.5 = 0.8 mika
Ka nuipa o ke kaula (m) = 200 grams = 0.2 kg
Alapine (f) = 50 Hz
Ka nui o ke kaula (µ) = m/l = 0.2 kg / 1.2 mika = (1/6) kg/mika
Makemake ʻia: Ka wā o ka nalu (T) a me ka ikaika o ke kaula (T)
Lōlā:
Ka wā o ka nalu:
T = 1 / f = 1 / 50 Hz = 0.02 kekona
Ka wikiwiki o ka nalu ma ke kaula:
v = f λ = (50 Hz)(0.8 mika) = 40 mika/kekona
ʻO ka ikaika hoʻopaʻa (T):
ʻO ka pane pololei ʻo C.
