4 mau laʻana o nā nīnau mokulele hilig SMP
1. E nānā i ke kiʻi ma lalo nei!
Ua huki ʻia kahi kaʻa ukana he 10 N ke kaumaha mai ka lalo o kahi mokulele hilig a hiki i ka piko o ka mokulele hilig. ʻO ka nui o ka ikaika F e pono ai…
A. 15,0 N
B. 12,5 N
C. 5,0 N
D. 2,5 N
Pahana
Ua ʻike ʻia:
Kaumaha o ke kaʻa (w) = 10 Newton
Ka lōʻihi o ka mokulele hilig = 2 mika
Ke kiʻekiʻe o ka mokulele hilig = 0,5 mika
θ = ke kihi ma waena o kahi mokulele pālahalaha a me kahi mokulele hilig
Sin θ = 0,5/2 = 0,25
Nīnau: Ka nui o ka ikaika F
Pane:
ʻO w x ka ʻāpana o ke kaumaha o ke kaʻa e kūlike ana me ka mokulele inclined
ʻO w y ka ʻāpana o ke kaumaha o ke kaʻa e kū pololei ana i ka mokulele inclined
I mea e huki ʻia ai ke kaʻa i luna, pono ka ikaika huki F e like me wx ma ka liʻiliʻi.
w x = w sin θ = (10 Newton)(0,25) = 2,5 Newton
No laila, ʻo ka ikaika tensile F = 2,5 Newton
ʻO D ka pane pololei.
2.
E hāpai ʻia kahi mea i hana ʻia me kahi poloka lāʻau laumania ma luna o kahi mokulele hilig laumania e like me ka mea i hōʻike ʻia ma ke kiʻi. Inā he 6 kg ke kaumaha o ka poloka, g = 10 m/s2, a laila ʻo ka nui o ka ikaika e hoʻokuke ai e hāpai i ka poloka mai P a i Q he…
A. 36 Newtons
B. 24 Newton
C. 20 Newton
D. 12 Newton
Pahana
Berat kukuna: w = mg = (6)(10) = 60 kg m/s2 = 60 Newton
He laumania nā poloka laumania a me nā mokulele hilig no laila ua manaʻo ʻia ʻaʻohe o lākou friction. ka ʻūmiʻiI mea e hoʻoneʻe ʻia ai ka poloka i luna, pono e like ka ikaika hoʻokuʻi liʻiliʻi me ka ʻāpana o ke kaumaha o ka poloka e kūlike ana i ka mokulele inclined, ʻo ia hoʻi ʻo wx.
wx = w sin teta = (w)(ʻaoʻao mua/hypotenuse)
wx = (60)(20/60) = (60)(1/3) = 20 Newtons
ʻO C ka pane pololei.
3.
Makemake kekahi limahana e hoʻoneʻe i kahi pahu ma luna o kahi kalaka he 500 Newtons ke kaumaha me ka hoʻohana ʻana i kahi mokulele inclined e like me ka mea i hōʻike ʻia ma ke kiʻi ma lalo nei. Inā he 1,5 m ke kiʻekiʻe o ke kalaka, ehia ka ikaika e pono ai e hoʻoneʻe i ka pahu?
A. 125 N
B. 250 N
C. 500 N
D. 1500 N
Pahana
Kaumaha o ka pahu (w) = 500 Newton
I mea e hoʻoneʻe ʻia ai ka pahu i luna, pono ka ikaika hoʻokuke liʻiliʻi loa e like me ka ʻāpana o ke koʻikoʻi o ka pahu e kūlike ana i ka mokulele inclined, ʻo ia hoʻi ʻo wx.
wx = w sin teta = (w)(ʻaoʻao mua/hypotenuse)
wx = (500)(1,5/3) = (500)(1/2) = 250 Newtons
ʻO ka pane pololei ʻo B.
4.
Pono e hāpai ʻia kahi ʻāpana lako kaumaha me ka hoʻohana ʻana i kahi papa e like me ka mokulele hilig, e like me ka mea i hōʻike ʻia ma ke kiʻi ma lalo nei. No ka hōʻoia ʻana he hapalua ka ikaika hāpai o ke kaumaha maoli o ka pahu, he papa me ka lōʻihi o...
A. 5,0 m
B. 7,5 m
C. 10,0 m
D. 12,5 m
Pahana
Kaumaha o ka pahu = w
I mea e hoʻoneʻe ʻia ai ka pahu i luna, pono e like ka ikaika hoʻokuʻi liʻiliʻi me ka ʻāpana o ke koʻikoʻi o ka pahu e kūlike ana i ka mokulele inclined, ʻo ia hoʻi ʻo wx. No laila, ʻo ka nui o ka ikaika e paʻi ana he 0,5 manawa o ke kaumaha o ka pahu, ʻo ka lōʻihi o ka papa…
wx = w sin teta
wx = (w)(ʻaoʻao mua/hypotenuse)
0,5 (w)= (w)(2,5/x)
0,5 = (2,5/x)
x = 2,5/0,5 = 5 mika
ʻO A ka pane pololei.
Puna nīnau:
Nā Nīnau Hoʻokolohua ʻEpekema Lahui no ke Kula Kiʻekiʻe Haʻahaʻa/Kula Kiʻekiʻe ʻIslama
