Examples of Inelastic Collisions in Everyday Life

📚 Quick Study Guide

• 💥 Inelastic collisions involve a loss of kinetic energy, usually converted into heat or sound.
• 🚗 Momentum is conserved in all collisions (elastic and inelastic), assuming no external forces.
• 📏 Kinetic energy is *not* conserved. $K_f < K_i$
• 🌡️ Energy is transformed into other forms, such as thermal energy (heat) and sound.
• 🧱 Examples include car crashes, dropping a ball of clay, or a bullet hitting a target.
• 📐 Coefficient of Restitution ($e$) is 0 for perfectly inelastic collisions (objects stick together).
• 🤝 Final velocities of the colliding objects are not equal in most cases, except when they stick together.

Practice Quiz

1. Which of the following is a key characteristic of an inelastic collision?
   1. Kinetic energy is conserved.
   2. Momentum is not conserved.
   3. Kinetic energy is converted to other forms of energy.
   4. The objects bounce perfectly apart.


2. In an inelastic collision, what happens to the total momentum of the system (assuming no external forces)?
   1. It increases.
   2. It decreases.
   3. It remains constant.
   4. It becomes zero.


3. A car crash is a classic example of an inelastic collision. What primarily happens to the kinetic energy in such a collision?
   1. It is completely conserved.
   2. It is mostly converted into heat and sound.
   3. It is converted back into potential energy.
   4. It disappears entirely.


4. A ball of clay is dropped onto the floor and sticks. What is the coefficient of restitution ($e$) for this collision?
   1. $e = 1$
   2. $e > 1$
   3. $e = 0$
   4. $0 < e < 1$


5. Two objects collide inelastically and stick together after the collision. What can be said about their final velocities?
   1. They have different final velocities.
   2. They have the same final velocity.
   3. One is at rest.
   4. They move in opposite directions.


6. Which of these scenarios best represents an inelastic collision?
   1. A rubber ball bouncing perfectly on a hard floor.
   2. Two billiard balls colliding and rebounding.
   3. A bullet embedding itself in a wooden block.
   4. A perfectly elastic spring pushing two objects apart.


7. In an inelastic collision, if the kinetic energy is not conserved, what happens to the "missing" energy?
   1. It transforms into potential energy.
   2. It is converted into mass.
   3. It is transformed into other forms of energy, such as heat and sound.
   4. It disappears from the system.