Question

a bomb of mass 3kg initially at rest explodes into two partsof 2kg ang 1kg.the 2kg mass travels with a velocity of3m/s at what velocity will 1kg mass travel?

Answer 1

We know that during fragmentation (explosion) of any material the particles possess equal Kinetic motion which is given by the formula
KE=$\frac{1}{2}$mv².
In the first particle , m=2 kg ,v= 3 m/s
⇒KE=$\frac{1}{2}$* 2 * 3² J
=$\frac{1}{2}$ *2 * 9 J
= 9 J
In the second particle let the required velocity be v.
The kinetic energy of both particles need to be equal.
⇒$\frac{1}{2}$*1*v² =9
or,v²=9*2=18
or, v=√18
Ans:The velocity of the piece of 1 kg is √18 m/s.