A firecracker explodes in midair and breaks up into many fragments.Which of the following statements are true regarding conditions immediately before and immediately after the explosion?
I.The total momentum of the fragments is equal to the original momentum of the firecracker.
II.The total kinetic energy of the fragments is equal to the original kinetic energy of the firecracker.
A)Statement I only
B)Statement II only
C)Both Statement I and Statement II
D)Neither statement is true.

Question

Quizplus · Accepted Answer

According to the principle of conservation of momentum, the total momentum of an isolated system remains constant unless acted upon by an external force. In this case, there are no external forces acting on the system of fragments, so the total momentum of the fragments must be equal to the momentum of the original firecracker. However, the explosion of the firecracker converts some of its internal energy into kinetic energy of the fragments, so the total kinetic energy of the fragments is generally less than the original kinetic energy of the firecracker. Therefore, Statement II is not true.

A Firecracker Explodes in Midair and Breaks Up into Many