Posted by Mary Grace on .
A bullet with a mass of 10 imbeds itself in a wooden block of mass 3990g and is free to move. If the speed of the block and bullet together is 50 cm/s just after the impact what was the original speed of the bullet ?
what was the right formula to use.? pls anwer me.

Physics 
Elena,
m1•v1=(m1+m2)v
v1=(m1+m2)v/m1=(0.01+3.99)0.5/0.01=200 m/s