Question

19. A free body of mass 8 kg is travelling at 2 meter per
second in a straight line. At a certain instant, the
body splits into two equal parts due to internal
explosion which releases 16 joules of energy.
Neither part leaves the original line of motion finally
1) Both parts continue to move in the same
direction as that of the original body
2) One part comes to rest and the other moves in
the same direction as that of the original body
3) One part comes to rest and the other moves in
the direction opposite to that of the original
body
4) One part moves in the same direction and the
other in the direction opposite to that of the
original body
Option 1​

Answer 1

Answer:

When the mass splits into two equal parts, the energy released is 16 joules so, this energy will released as kinetic energy and since both the parts have same mass so, each part will have kinetic energy 8 joules but both the mass will move in the opposite direction as the linear momentum of the mass has to conserve.

the expression for kinetic energy is KE=

2

mv

2

so, the velocity of each part is,

v

2

=

4 kg

2(KE)

v=

4 kg

2(KE)

v=2 m/s

since, the both parts will move in the opposite direction and the initial velocity of the mass was 2 ms so, one mass will come to rest and the another will move in the same direction.

So, the correct answer is ,B