36. Which of the following values is closest to the minimum power in hp required for a 1000-kg car that is climbing a 5.7° hill at a steady 72 km/h? Assume that the average drag force on the car at that speed is 500 N throughout. (g = 10 m/s2 , 1 hp = 750 W)
(A) 5
(B) 20
(D) 100
(E) 300
(C) 40

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統計： A(0), B(1), C(0), D(0), E(2) #2993335

詳解 (共 1 筆)

#7295226
drag force：阻力
F (總牽引力) = F drag + mgsinθ
sin5.7o =1
F= 500+1000 x sin5.7o =1500 N
P=Fv
P=1500 x 200 = 30000W = 40 hp
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