Perfectly Inelastic Collisions

Definition

A perfectly inelastic collision is a type of collision where two or more objects collide and stick together, resulting in a single object with a combined mass and momentum after the collision. In this type of collision, the kinetic energy of the system is not conserved, as some of the energy is lost in the deformation of the objects during the collision.

5 Must Know Facts For Your Next Test

1. In a perfectly inelastic collision, the colliding objects stick together and move with a common velocity after the collision.
2. The total momentum of the system is conserved in a perfectly inelastic collision, but the kinetic energy of the system is not conserved.
3. The loss of kinetic energy in a perfectly inelastic collision is due to the deformation and internal heating of the colliding objects.
4. Perfectly inelastic collisions are often used to measure the mass of an object, as the combined mass of the colliding objects can be determined from the final velocity of the system.
5. Perfectly inelastic collisions are commonly observed in real-world situations, such as the collision of a bullet with a target, the collision of a car with a wall, or the collision of two atoms in a particle accelerator.

Review Questions

• Explain the key difference between a perfectly inelastic collision and an elastic collision.
  • The key difference between a perfectly inelastic collision and an elastic collision is the conservation of kinetic energy. In an elastic collision, the kinetic energy of the system is conserved, meaning that the total kinetic energy before the collision is equal to the total kinetic energy after the collision. In a perfectly inelastic collision, however, the kinetic energy of the system is not conserved, as some of the energy is lost due to the deformation and internal heating of the colliding objects. This loss of kinetic energy is a defining characteristic of perfectly inelastic collisions.
• Describe how the final velocity of the combined object in a perfectly inelastic collision can be used to determine the masses of the colliding objects.
  • In a perfectly inelastic collision, the colliding objects stick together and move with a common velocity after the collision. This final velocity can be used to determine the masses of the colliding objects, as the total momentum of the system is conserved. Specifically, the final velocity of the combined object is inversely proportional to the sum of the masses of the colliding objects. By measuring the final velocity and knowing the initial velocities and masses of the colliding objects, it is possible to calculate the masses of the individual objects involved in the collision.
• Analyze the role of kinetic energy conservation in distinguishing between perfectly inelastic collisions and other types of collisions, such as elastic collisions.
  • The conservation of kinetic energy is a crucial factor in distinguishing between perfectly inelastic collisions and other types of collisions. In an elastic collision, the kinetic energy of the system is conserved, meaning that the total kinetic energy before the collision is equal to the total kinetic energy after the collision. This is not the case in a perfectly inelastic collision, where the kinetic energy of the system is not conserved due to the deformation and internal heating of the colliding objects. By analyzing the conservation (or lack thereof) of kinetic energy, it is possible to determine the type of collision that has occurred and make inferences about the properties of the colliding objects, such as their masses and the forces involved in the collision.

Related terms

Inelastic Collision: An inelastic collision is a type of collision where the kinetic energy of the system is not conserved, as some of the energy is lost in the deformation of the objects during the collision.

Momentum Conservation: Momentum conservation is a fundamental principle in physics that states that the total momentum of a closed system is constant, unless an external force acts on the system.

Kinetic Energy: Kinetic energy is the energy of motion, which an object possesses by virtue of being in motion.