Question

As a delivery truck travels along a level stretch of road with constant speed, most of the power developed by the engine is used to compensate for the energy transformations due to friction forces exerted on the delivery truck by the air and the road. If the power developed by the engine is 5.15 hp, calculate the total friction force acting on the delivery truck (in N) when it is moving at a speed of 30 m/s. One horsepower equals 746 W.

Answer 1

Answer:

128 N

Explanation:

Power can be defined as

$P = F\cdot v$

F is the force and v is the velocity.

$F = \dfrac{P}{v}$

According to the question, P = 5.15 hp = 5.15 × 746 W.

v = 30 m/s

$F = \dfrac{5.15\times 746\text{ W}}{30\text{ m/s}} = 128 \text{ N}$

Since most of the power is used to compensate for the energy transformations due to friction forces, the total frictional is 128 N