Question

A car of mass 960.0 kg accelerates away from an intersection on a horizontal road. When the car speed is 51.1 km/hr (14.2 m/s), the net power which the engine supplies is 3700.0 W (in addition to the extra power required to make up for air resistance and friction). Calculate the acceleration of the car at that time.

Answer 1

Answer:

$0.27 m/s^2$

Explanation:

The power supplied by the engine is given by

P = Fv

where

F is the force applied

v is the velocity of the car

Here we have

P = 3700 W

v = 14.2 m/s

So we can solve the equation to find the average force:

$F=\frac{P}{v}=\frac{3700 W}{14.2 m/s}=260.6 N$

The net force applied on the car is also equal to

F = ma

where

m = 960.0 kg is the mass of the car

a is the acceleration

Re-arranging the equation, we find the acceleration:

$a=\frac{F}{m}=\frac{260.6 N}{960.0 kg}=0.27 m/s^2$