A bomb is kept stationary at a point. It suddenly explodes into two fragments of masses 1 g  and 3 g. The total K.E. of the fragments is 6.4×104J. What is the K.E. of the smaller fragment

As the momentum of both fragments are equal therefore E1E2=m2m1=31 i.e. E1=3E2       …(i)According to problem  E1+E2=6.4×104J                                                                          …(ii) By solving equation (i) and (ii) we get E1=4.8×104J  and  E2=1.6×104J