Question

Calculate the kinetic energy of a car which has a mass of 1000 kg and is moving at the rate of 20 m/s.

Answer 1

Given,

The mass of the car, m=1000 kg

The velocity of the car, v=20 m/s

The kinetic energy of an object is the energy of the body possessed due to its motion. The kinetic energy of a body is directly proportional to the square of the velocity of the object.

The kinetic energy of the car is given by,

$E=\frac{1}{2}mv^2$

On substituting the known values,

$\begin{gathered} E=\frac{1}{2}\times1000\times20^2 \\ =200000\text{ J} \\ =200\text{ kJ} \end{gathered}$

Thus the kinetic energy of the given car is 200 kJ.