Perfectly Inelastic Collision Quiz with Answers: Test Your Knowledge

📚 Quick Study Guide

• 🔍 Definition: A perfectly inelastic collision is one where objects stick together after colliding.
• 🤝 Key Characteristic: Kinetic energy is not conserved; some is converted into other forms of energy like heat or sound.
• 📏 Conservation of Momentum: Total momentum is conserved in all types of collisions (including perfectly inelastic ones).
• ➗ Formula for Momentum Conservation: $m_1v_1 + m_2v_2 = (m_1 + m_2)v_f$, where $v_f$ is the final velocity of the combined mass.
• 🌡️ Energy Loss: The loss of kinetic energy can be calculated, often resulting in heat.
• 💡 Real-world Examples: Car crashes where vehicles crumple and stick together, or a bullet embedding in a target.
• 📝 Note: Remember to use consistent units (e.g., kg for mass, m/s for velocity).

🧪 Practice Quiz

1. A 2 kg ball moving at 3 m/s collides head-on with a 1 kg ball at rest. The balls stick together. What is their final velocity?
   1. A) 1 m/s
   2. B) 2 m/s
   3. C) 3 m/s
   4. D) 4 m/s
2. In a perfectly inelastic collision, which of the following is always conserved?
   1. A) Kinetic Energy
   2. B) Potential Energy
   3. C) Momentum
   4. D) Velocity
3. A 5 kg mass moving at 2 m/s collides with a 5 kg mass at rest in a perfectly inelastic collision. What is the final kinetic energy of the system?
   1. A) 2.5 J
   2. B) 5 J
   3. C) 10 J
   4. D) 20 J
4. Two cars collide head-on and stick together. Car A (1000 kg) was moving at 20 m/s, and Car B (1500 kg) was moving at -10 m/s. What is the final velocity of the wreckage?
   1. A) -2 m/s
   2. B) 2 m/s
   3. C) 5 m/s
   4. D) 8 m/s
5. Which of the following best describes a perfectly inelastic collision?
   1. A) Objects bounce off each other with no energy loss.
   2. B) Objects stick together, and kinetic energy is conserved.
   3. C) Objects stick together, and kinetic energy is not conserved.
   4. D) Objects separate with increased kinetic energy.
6. A bullet (0.05 kg) is fired at 200 m/s into a stationary block of wood (2 kg). The bullet becomes embedded in the wood. What is the velocity of the wood block immediately after impact?
   1. A) 2 m/s
   2. B) 4.88 m/s
   3. C) 5 m/s
   4. D) 10 m/s
7. What happens to the total kinetic energy in a perfectly inelastic collision?
   1. A) It increases.
   2. B) It decreases.
   3. C) It remains the same.
   4. D) It becomes zero.