Question

Which of the following best describes a completely elastic collision?

The kinetic energy (K) of the system before the collision equals K after.

The potential energy (U) of the system before the collision equals U after.

The kinetic energy (K) of the system before the collision is greater than K after.

The kinetic energy (K) of the system before the collision is less than K after.,

Answer 1

The answer is (a): The kinetic energy of the system before the collision equals the energy after the collision. An completely elastic collision is one in which no kinetic energy is lost or gained in a collision between two things. In elastic collisions, two things bounce off of each other at the same speed at which they were moving when they collided. This does not usually happen in collisions because energy is lost through collision; however, some gaseous atoms are able to collide without losing kinetic energy.

Answer 2

The kinetic energy (K) of the system before the collision equals K after.

Step-by-step explanation:

An elastic collision is a collision in which there is no net loss in kinetic energy from the system as a result of the collision. The amount of motion and the kinetic energy are conserved quantities in elastic collisions. This means that the kinetic energy (K) of the system before the collision equals K after.

Some collisions between atoms in gases are examples of perfectly elastic collisions.