Question

A car has a mass of 1500 kg moves with a speed of 40 m/s. If the car speeds up to 50 m/s. How much is the work done by the car engine?

Answer 1

Given:

$m=1500\:\rm kg$

$v_1=40\:\rm m/s$

$v_2=50\:\rm m/s$

The energy-work theorem says

$$W=\Delta E=\frac{mv_2^2}{2}-\frac{mv_1^2}{2}$$

$$W=\frac{1500*(50)^2}{2}-\frac{1500*(40)^2}{2}=675 000\: \rm J$$