Question

A car (1000 kg) climbs up a hill sloped at 28° while traveling at constant speed of 75 km/hr, what is the power (kW) required for the uphill motion? Select one: O a. power 95.9 kW. O b. power 119.7 kW. c. power 89.6 kW. d. power 108.7 kW. e power 102.3 kW.

Answer 1

At constant velocity, there is no change in kinetic energy, so the net work done to move the car is zero. So the car will move up the hill using the gravity and air resistance.

Therefore, we know that the power required to move the car up the hill is

$Power(P) = m g v sin\theta$

Where, m is mass of the car in Kg.

g is acceleration due to gravity 9.81m/s².

v is speed of car in m/s.

Given Data is

Mass of the car (m) = 1000kg

Speed of the car (v) = 75 km/hr = 75* (5/18) =20.833 m/s.

Angle of inclination ($\theta$) = 28⁰.

Now therefore,

So the answer is Option A .