Can Kinetic Energy Be Completely Lost in a Collision?

[TwinGemini14]

It is not possible for a system to lose all of its kinetic energy in a collision.

A) True
B) False

This question seems really tricky, but I believe the answer to be A: true. Even if two identical masses are approaching each other head-on at the same velocity (two billiard balls), when they collide they bounce off each other and continue with KE. Is this right?

 

[LowlyPion]

It is not possible for a system to lose all of its kinetic energy in a collision.

A) True
B) False

This question seems really tricky, but I believe the answer to be A: true. Even if two identical masses are approaching each other head-on at the same velocity (two billiard balls), when they collide they bounce off each other and continue with KE. Is this right?

That is true for elastic collisions.

What about inelastic collisions - say 2 equal balls of damp clay that deform and stick together?

 

[nlightner]

I can confirm that the answer is A: True. In a collision, the total kinetic energy of a system is conserved, meaning it cannot be lost. It can only be transferred between objects involved in the collision. This is known as the law of conservation of energy. Even in the scenario described, where two identical masses collide head-on, there will still be some kinetic energy present after the collision. This is because some of the kinetic energy of the system will be transferred to other forms, such as heat or sound. Therefore, it is not possible for a system to lose all of its kinetic energy in a collision.