An object of mass 2 kg is moving with a velocity of 20 m/s then its kinetic energy must be ____

Mass, m = 2 kg
Velocity, v = 20 m/s
Kinetic Energy (K.E) = ?

Kinetic energy of a particle is given by $\mathrm{K}.\mathrm{E}=\frac{1}{2}\times {\mathrm{mv}}^2$
$\Rightarrow \mathrm{K}.\mathrm{E}=\frac{1}{2}\times \left(2\right)\times (20{)}^2$

$\Rightarrow \mathrm{K}.\mathrm{E}=400 \mathrm{J}$

Therefore, the kinetic energy of the body will be 400 J.