Write the definition of work and kinetic energy.

(N/A) Work: The product of the magnitude of force and the displacement in the direction of the force is called work.
$\therefore$ Work $=$ Force $\times$ Displacement
If the force and the displacement are in the same direction,the work done is positive. If they are in opposite directions,the work done is negative. If the force is perpendicular to the displacement,the work done is zero.
Kinetic Energy: The energy possessed by a body by virtue of its motion is known as kinetic energy.
Alternatively,kinetic energy is defined as half of the product of the mass of a body and the square of its velocity.
$\therefore$ Kinetic energy $= \frac{1}{2} m v^{2}$
where $m$ is the mass of the body and $v$ is the velocity of the body.