Question 1: Momentum is a measure of the quantity of motion an object has. It is the product of an object's mass and its velocity. Momentum is a vector quantity, having both magnitude and direction.

Answer: Momentum = mass × velocity (p = mv)

Question 1: Define what is meant by the conservation of momentum.

Answer: In a closed system with no external forces, the total momentum before an interaction equals the total momentum after.

Question 2: Explain why momentum is considered a vector quantity and how its direction affects calculations.

Answer: Momentum has both magnitude and direction; when calculating total momentum, vectors must be added considering their directions to obtain the correct resultant.

Question 1: A car with a mass of 1500 kg is travelling at a velocity of 20 m/s. Calculate its momentum.

Answer: p = 1500 kg × 20 m/s = 30000 kg·m/s

Question 2: A cyclist with a mass of 70 kg is moving at a velocity of 5 m/s. What is the cyclist's momentum?

Answer: p = 70 kg × 5 m/s = 350 kg·m/s

Question 1: Describe a simple experiment to investigate how the momentum of a trolley changes when it collides with a barrier. List the variables you would control and measure, and mention safety precautions.

Answer: Set up a trolley on a smooth track with a motion sensor or stopwatch to measure velocity before and after collision. Control variables include mass of the trolley and initial velocity. Measure the velocities and calculate momentum before and after. Safety precautions include ensuring the track is clear and the collision area is secure to prevent injuries.

Question 2: Identify two real-world scenarios where understanding momentum is crucial for safety and efficiency.

Answer: Car braking systems and spacecraft re-entry procedures.

Question 1: A truck of mass 3000 kg is moving at 10 m/s and collides with a stationary vehicle of mass 1500 kg. Assuming an inelastic collision, explain how the principle of conservation of momentum applies and estimate the velocity of the combined vehicles after impact.

Answer: Total initial momentum = (3000 kg × 10 m/s) + (1500 kg × 0 m/s) = 30000 kg·m/s. In an inelastic collision, the vehicles stick together, so total momentum after collision = (mass1 + mass2) × final velocity. Final velocity = total initial momentum / total mass = 30000 / 4500 ≈ 6.67 m/s in the initial direction of the truck.

Question 1: Explain how understanding momentum is important in the design of safety features such as airbags and crumple zones in vehicles.

Answer: Understanding momentum allows engineers to design features that increase the time over which a collision occurs, thereby reducing the force experienced by passengers and improving safety.