Perfectly Inelastic Collision Quiz: Test Your Knowledge

📚 Quick Study Guide

• 💥 Definition: A perfectly inelastic collision is one where the maximum amount of kinetic energy is lost. This results in the colliding objects sticking together after impact.
• 📝 Key Characteristic: Objects stick together after the collision.
• 📐 Momentum Conservation: Momentum is always conserved in collisions (elastic, inelastic, or perfectly inelastic) in a closed system. The formula is: $m_1v_1 + m_2v_2 = (m_1 + m_2)v_f$, where $v_f$ is the final velocity of the combined mass.
• 🔥 Kinetic Energy Loss: Kinetic energy is not conserved. The lost kinetic energy is often converted into heat or sound.
• 💡 Coefficient of Restitution: The coefficient of restitution (e) is 0 for perfectly inelastic collisions. $e = \frac{v_2' - v_1'}{v_1 - v_2} = 0$

🧪 Practice Quiz

1. What is the primary characteristic of a perfectly inelastic collision?
   1. The objects bounce off each other.
   2. The objects stick together.
   3. Kinetic energy is conserved.
   4. Momentum is not conserved.
2. In a perfectly inelastic collision, what happens to the kinetic energy?
   1. It is conserved.
   2. It is increased.
   3. It is decreased.
   4. It remains constant.
3. Which of the following is true about momentum in a perfectly inelastic collision?
   1. Momentum is not conserved.
   2. Momentum is conserved.
   3. Momentum is sometimes conserved.
   4. Momentum is doubled.
4. What is the coefficient of restitution (e) for a perfectly inelastic collision?
   1. e = 1
   2. e > 0
   3. e < 0
   4. e = 0
5. Two objects with masses $m_1$ and $m_2$ collide perfectly inelastically with initial velocities $v_1$ and $v_2$ respectively. What is their final velocity ($v_f$) after the collision?
   1. $v_f = \frac{m_1v_1 + m_2v_2}{m_1 + m_2}$
   2. $v_f = \frac{m_1v_1 - m_2v_2}{m_1 + m_2}$
   3. $v_f = m_1v_1 + m_2v_2$
   4. $v_f = \frac{m_1 + m_2}{m_1v_1 + m_2v_2}$
6. In a perfectly inelastic collision, what form does the lost kinetic energy often take?
   1. Potential energy
   2. Chemical energy
   3. Heat and sound
   4. Nuclear energy
7. A 2 kg object moving at 3 m/s collides perfectly inelastically with a 1 kg stationary object. What is the final velocity of the combined mass?
   1. 1 m/s
   2. 2 m/s
   3. 3 m/s
   4. 4 m/s