A 1321-kg car climbs a 5.0° slope at a constant speed of $80.0 \mathrm {~km} / \mathrm { h }$ Assuming that air resistance may be neglected, at what rate (in kW) must the engine deliver energy to the drive wheels of the car?
A) 25 kW
B) 287 kW
C) 38 kW
D) 48 kW

Question

Quizplus · Accepted Answer

The power required to overcome the force of gravity is:$$P = Fv = mgsv$$$$P = (1321 \mathrm {~kg})(9.80 \mathrm {~m} / \mathrm {~s} ^2)(\sin 5.0 ^\circ)(80.0 \mathrm {~km} / \mathrm {~h})(1000 \mathrm {~m} / \mathrm {~km})(1 \mathrm {~h} / 3600 \mathrm {~s})$$$$P = 287 \mathrm {~kW}$$

A 1321-Kg Car Climbs a 5 80.0 km/h80.0 \mathrm {~km} / \mathrm { h }80.0 km/h

A 1321-Kg Car Climbs a 5 $80.0 \mathrm {~km} / \mathrm { h }$