Question

What is the kinetic energy of a 1,500-kg car traveling at 110 kph if the car can reach this velocity in 12 seconds starting from rest? What is the power output of the engine in HP?

Answer 1

Given:

$m=1500\:\rm kg$

$v=110\:\rm km/h=30.6\:\rm m/s$

$t=12\:\rm s$

$$P=\frac{W}{t}=\frac{\Delta E}{t}=\frac{mv^2}{2t}$$

$$P=\frac{1500*30.6^2}{2*12}=5.84*10^4\:\rm W=78.3\:hp$$