The unit of the physical quantity expressed by equation $\frac{p^2}{2m}$ is: (p is momentum and m is mass)

joule

Reason — As momentum p = mv, so

$\frac{p^2}{2m} = \frac{(mv)^2}{2m} = \frac{m^2v^2}{2m} = \frac{1}{2}mv^2$

which is the expression for kinetic energy. Since energy is measured in joule, the unit of $\frac{p^2}{2m}$ is joule.