Elastic Collision

Definition

An elastic collision is a type of collision between two objects in which there is no net loss of kinetic energy. The total kinetic energy of the colliding objects before the collision is equal to the total kinetic energy after the collision, and the objects may bounce off each other.

5 Must Know Facts For Your Next Test

1. In an elastic collision, the total kinetic energy of the colliding objects is conserved, meaning it is the same before and after the collision.
2. The velocities of the objects may change direction and magnitude, but the total momentum of the system is conserved.
3. Elastic collisions are often used to model the behavior of particles in physics, such as in the kinetic theory of gases.
4. The coefficient of restitution, a measure of the elasticity of a collision, is equal to 1 for a perfectly elastic collision.
5. Elastic collisions can be observed in everyday phenomena, such as the bouncing of a rubber ball or the collision of billiard balls on a pool table.

Review Questions

• Explain how the principle of conservation of momentum applies to an elastic collision.
  • In an elastic collision, the total momentum of the colliding objects is conserved. This means that the sum of the momenta of the objects before the collision is equal to the sum of the momenta of the objects after the collision. The velocities of the objects may change, but the total momentum remains the same. This is a fundamental principle in the study of linear momentum, force, and impulse.
• Describe how the concept of kinetic energy relates to an elastic collision.
  • In an elastic collision, the total kinetic energy of the colliding objects is also conserved. This means that the sum of the kinetic energies of the objects before the collision is equal to the sum of the kinetic energies of the objects after the collision. The objects may exchange kinetic energy, but the total kinetic energy of the system remains the same. This is a key distinction between elastic and inelastic collisions, where kinetic energy is not conserved.
• Analyze the role of the coefficient of restitution in determining the nature of an elastic collision.
  • The coefficient of restitution is a measure of the elasticity of a collision, ranging from 0 (completely inelastic) to 1 (perfectly elastic). In an elastic collision, the coefficient of restitution is equal to 1, indicating that no kinetic energy is lost during the collision. This means that the velocities of the objects before and after the collision are related by the coefficient of restitution, allowing for the prediction of the final velocities based on the initial velocities and the coefficient of restitution.

Related terms

Momentum: Momentum is the product of an object's mass and velocity, and is conserved in an elastic collision.

Conservation of Momentum: The principle that the total momentum of a closed system is conserved, meaning the total momentum before a collision is equal to the total momentum after the collision.

Inelastic Collision: An inelastic collision is a type of collision in which kinetic energy is not conserved, and some of the kinetic energy is converted to other forms of energy, such as heat or sound.