10000 small balls, each weighing 1 g, strikes 1 cm² of area per second with a velocity $100 {\mathrm{ms}}^{-1}$ in a normal direction and rebound with the same velocity. The value of pressure on the surface will be

• A

  $2 \times {10}^3 {\mathrm{Nm}}^{-2}$

• B

  $2 \times {10}^5 {\mathrm{Nm}}^{-2}$

• C

  ${10}^7 {\mathrm{Nm}}^{-2}$

• D

  $2 \times {10}^7 {\mathrm{Nm}}^{-2}$