Question 1: Define momentum in physics and state its SI unit.

Answer: Momentum is the product of an object's mass and its velocity; its SI unit is kilogram metre per second (kg·m/s).

Question 2: Explain why momentum is considered a vector quantity.

Answer: Because momentum has both magnitude and direction, depending on the direction of the velocity.

Question 3: Describe what happens to the total momentum when two objects collide elastically.

Answer: The total momentum before and after the collision remains the same, due to conservation of momentum.

Question 4: Calculate the momentum of a car with mass 1500 kg travelling at 20 m/s.

Answer: Momentum = mass × velocity = 1500 kg × 20 m/s = 30,000 kg·m/s

Question 5: A bicycle of mass 15 kg is moving at 10 m/s. What is its momentum?

Answer: Momentum = 15 kg × 10 m/s = 150 kg·m/s

Question 6: Which of the following objects has the greatest momentum? A 2 kg ball moving at 5 m/s, a 1 kg ball moving at 8 m/s, or a 4 kg ball moving at 3 m/s? (Select the correct option)

Answer: 1 kg ball at 8 m/s

Question 7: Fill in the blank: The law of conservation of momentum states that in a closed system, the total momentum ________ over time.

Answer: remains constant

Question 8: Describe a real-world scenario where understanding momentum is essential for safety.

Answer: Understanding momentum is crucial in car safety features like airbags and crumple zones, which are designed to reduce the force during collisions by increasing the time over which the vehicle's momentum changes, thereby reducing injury.

Question 9: Identify and explain two variables that affect an object's momentum.

Answer: The object's mass and velocity; increasing either will increase the momentum.

Question 10: Discuss how momentum is involved in the operation of a sports car braking system.

Answer: When a sports car brakes, its momentum decreases as the brake system applies a force over time, converting kinetic energy into heat. The effectiveness of braking depends on the initial momentum, which is influenced by the car's mass and velocity, and the design of the braking mechanism to safely reduce this momentum within a controlled distance.