Question

A bomb of mass 5 kg is projected vertically upwars with a velocity of 40 ms it explodes into two equal parts after 4 sec. after explosion if one of the pie es is flying upwatds with velocity 2 ms find the velocity of another piece

Answer 1

The velocity of the bomb after 4 seconds when it explodes is

$v=u-gt\\ v=40-10(4)\\ v=0$

Since the momentum is conserved, momentum before after explosion remains the same. Momentum before explosion is 0

$m(0)=\frac{m}{2} (2)+\frac{m}{2} (v)\\ 0=\frac{m}{2} (2)+\frac{m}{2} (v)\\ v=-2$

The velocity of the other piece is $-2 \;m/s$. The other piece is travelling downwards at $2 \;m/s$.