A space craft of mass M is moving with velocity v in free space when it explodes and breaks in two. After the explosion, a mass m of the space craft is Left stationary. What is the velocity of other part ?

• A

  $\mathrm{Mv}/(\mathrm{M}-\mathrm{m})$

• B

  $\mathrm{mv}/(\mathrm{M}+\mathrm{m})$

• C

  $\mathrm{mv}/(\mathrm{m}-\mathrm{M})$

• D

  $(\mathrm{M}+\mathrm{m})\mathrm{v}/\mathrm{M}$