Question

An electric car is being driven through a town at 22 m/s. The kinetic energy of the car is 222640J. Calculate the mass of the car

Answer 1

By the definition of the kinetic energy, we have:

$$KE=\dfrac{1}{2}mv^2,$$ $$m=\dfrac{2KE}{v^2},$$ $$m=\dfrac{2\cdot222640\ J}{(22\ \dfrac{m}{s})^2}=920\ kg.$$

Answer:

$m=920\ kg.$