A ball of mass m moves with speed v and it strikes normally with a wall and reflected back normally, if its time of contact with wall is t then find force exerted by ball on wall

• A

  $\frac{2\mathrm{mv}}{\mathrm{t}}$

• B

  $\frac{\mathrm{mv}}{\mathrm{t}}$

• C

  $\mathrm{mvt}$

• D

  $\frac{\mathrm{mv}}{2\mathrm{t}}$