Conservation of Linear Momentum Quiz with Answer Key

📚 Quick Study Guide

• ⚖️ Linear Momentum: The product of an object's mass ($m$) and its velocity ($v$). It's given by the formula: $p = mv$.
• ➡️ Conservation of Linear Momentum: In a closed system (no external forces), the total momentum remains constant. That means the total momentum before an interaction equals the total momentum after the interaction.
• 💥 Collisions: A classic example of momentum conservation. We can use the principle to analyze collisions between objects.
• 🧮 Formula for Conservation: For a two-object system: $m_1v_{1i} + m_2v_{2i} = m_1v_{1f} + m_2v_{2f}$, where 'i' denotes initial velocity and 'f' denotes final velocity.
• 🛑 Important Note: Momentum is a vector quantity, meaning direction matters. Account for direction using positive and negative signs.

Practice Quiz

1. A 2 kg bowling ball is traveling at 5 m/s. What is its momentum?
   1. A) 2.5 kg m/s
   2. B) 7 kg m/s
   3. C) 10 kg m/s
   4. D) 20 kg m/s
2. A 5 kg object moving at 3 m/s collides with a stationary 2 kg object. If they stick together, what is their final velocity?
   1. A) 1.07 m/s
   2. B) 2.14 m/s
   3. C) 4.29 m/s
   4. D) 7.5 m/s
3. A 0.1 kg bullet is fired from a 5 kg rifle. If the bullet's velocity is 300 m/s, what is the recoil velocity of the rifle?
   1. A) -6 m/s
   2. B) -3 m/s
   3. C) 3 m/s
   4. D) 6 m/s
4. Which of the following is NOT a condition for conservation of linear momentum?
   1. A) Closed system
   2. B) No external forces
   3. C) Elastic collision
   4. D) Isolated system
5. Two objects with equal mass are moving towards each other at the same speed. After an elastic collision, what is true about their velocities?
   1. A) They both stop
   2. B) They exchange velocities
   3. C) They move in the same direction
   4. D) One stops, the other doubles its speed
6. A 3 kg ball moving at 4 m/s hits a wall and bounces back at 2 m/s. What is the change in momentum of the ball?
   1. A) 6 kg m/s
   2. B) -6 kg m/s
   3. C) 18 kg m/s
   4. D) -18 kg m/s
7. In an inelastic collision, what quantity is NOT conserved?
   1. A) Momentum
   2. B) Kinetic Energy
   3. C) Mass
   4. D) Total Energy