What is kinetic energy and what is the kinetic energy of an object at rest

The formula for kinetic energy ($KE$) is given by:

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

where $m$ is the mass of the object and $v$ is its velocity.

An object at rest has a velocity ($v$) of $0\ \text{m/s}$. Substituting this into the kinetic energy formula:

$$KE = \frac{1}{2}m(0)^2$$ $$KE = \frac{1}{2}m(0)$$ $$KE = 0$$

Therefore, an object at rest has no kinetic energy.