Question

A stationary bomb explodes in space breaking into a number of small fragments. At the location of the explosion, the net force due to gravity is zero newtons. Which one of the following statements concerning this event is true? i)State principle involved. ii) Explain.A) Kinetic Energy is conserved in this process.B) All of the fragments must have equal kinetic energies.C) The sum of the kinetic energies of the fragments must be zero.D)The Vector sum of the linear momenta of the fragments must be zero.E) The mass of any one fragment must be equal to the mass of any other fragment.

Answer 1

Answer:

.D)The Vector sum of the linear momenta of the fragments must be zero.

Explanation:

.D)The Vector sum of the linear momenta of the fragments must be zero.

This statement is true. This is so because no external force is acting on the masses. The motion is created by internal force so momentum of fragments will be conserved.

A) this statement is false because kinetic energy was zero in the beginning ( the bomb was stationary in the beginning )

B ) This statement is false because it violates the law of conservation of momentum .( it does not violates only when all the fragments have equal mass )

C ) This statement is zero because kinetic energy is not a vector quantity so two kinetic energy when added can not sum up to zero.