Question 1: Define kinetic energy and describe how it is stored in an object.

Answer: Kinetic energy is the energy an object possesses due to its motion. It is stored in the moving object as energy of motion, which depends on its mass and velocity.

Question 2: Explain why a heavier object moving at the same speed as a lighter object has more kinetic energy.

Answer: Because kinetic energy depends on mass and velocity (KE = ½ m v²), a heavier object with the same speed has more kinetic energy due to the larger mass.

Question 3: Calculate the kinetic energy of a 1500 kg car travelling at 20 m/s.

Answer: KE = ½ m v² = ½ × 1500 kg × (20 m/s)² = 750 × 400 = 300,000 Joules

Question 4: Identify the factors that influence the amount of kinetic energy an object has.

Answer: The mass of the object and its velocity influence kinetic energy; increasing either increases the kinetic energy.

Question 5: A bicycle with a mass of 15 kg is moving at a speed of 10 m/s. What is its kinetic energy?

Answer: KE = ½ × 15 kg × (10 m/s)² = 7.5 × 100 = 750 Joules

Question 6: Which of the following objects has the greatest kinetic energy? A) A 2 kg ball moving at 5 m/s B) A 1 kg ball moving at 10 m/s C) A 4 kg ball moving at 3 m/s

Answer: B) 1 kg ball at 10 m/s

Question 7: Fill in the blank: The kinetic energy of an object **increases** with increasing __________ and __________ of the object.

Answer: mass; velocity

Question 8: Describe an experiment to demonstrate that kinetic energy increases with speed. Include the safety precautions you would take.

Answer: One possible experiment is to use a toy car on a ramp, measuring its speed at different heights (using a stopwatch or light gates). As the car accelerates down the ramp, its speed increases, and so does its kinetic energy. Safety precautions include ensuring the area around the ramp is clear, wearing safety goggles to protect eyes from any parts or debris, and making sure the ramp is stable and secure.

Question 9: Data shows that when a 10 kg object moves at 4 m/s, its kinetic energy is 80 Joules. What is its velocity if the kinetic energy is increased to 200 Joules, assuming mass remains constant?

Answer: KE = ½ m v²; 200 = ½ × 10 × v²; 200 = 5 v²; v² = 40; v = √40 ≈ 6.32 m/s

Question 10: In a real-world scenario, explain how kinetic energy is considered when designing safety features in vehicles.

Answer: Kinetic energy is important in crash safety design because it determines the force exerted during a collision. Safety features like airbags and crumple zones absorb and reduce the kinetic energy transfer, protecting passengers.