A bullet of mass 10g travelling horizontally at a speed of 100m/s embeds itself in a block of wood of mass 990g suspended by strings so that it can swing freely find:

Question

a.the vertical height through which the block rises.
B.how much of the bullet energy becomes internal energy (g

Answer 1

The law of conservation of linear momentum
mv=(m+M)u
The law of conservation of energy
u =mv/(m+M) = 0.01•100/(0.99+0.01)= 1 m/s.
(m+M)u²/2 =(m+M)gh
h= u²/2•g=1/2•9.8=0.05 m
mv²/2- (m+M)u²/2 = 0.01•10000/2 - 1•1/2 = 50-0.5=49.5 J