Question 1: Define gravitational potential energy (GPE).

Answer: GPE is the energy stored in an object due to its position relative to a reference point, usually due to gravity.

Question 2: State the formula used to calculate GPE and specify the units of each variable.

Answer: GPE = mgh, where m is mass in kilograms (kg), g is gravitational field strength in newtons per kilogram (N/kg), and h is height in metres (m).

Question 1: A 50 kg object is lifted to a height of 10 metres. Calculate the GPE stored in the object. (Use g = 9.8 N/kg)

Answer: GPE = 50 × 9.8 × 10 = 4900 Joules

Question 2: A 2 kg mass is dropped from a height of 5 metres. What is the GPE at the start of the fall?

Answer: GPE = 2 × 9.8 × 5 = 98 Joules

Question 1: Describe a simple experiment to measure the change in GPE of an object as it falls. Include the variables that need to be controlled and safety precautions.

Answer: The experiment involves lifting an object of known mass to a specific height and then releasing it to fall freely. Measure the height (h) before release. Variables to control include mass, height, and release method. Use a stable surface and ensure the fall area is clear to prevent injury. Use a stopwatch or motion sensor to measure velocity if needed. Record the initial GPE and any energy transferred during the fall to analyse energy conservation.

Question 1: A roller coaster car of mass 500 kg is lifted to the top of a hill 50 metres high. After the ride, it is at the bottom of the hill with negligible speed. Calculate the total GPE at the top and discuss how energy conservation applies during the ride.

Answer: GPE at the top: GPE = 500 × 9.8 × 50 = 245,000 Joules. As the car descends, GPE converts into kinetic energy, and assuming no losses, the GPE decreases while kinetic energy increases. At the bottom, GPE is nearly zero, and the kinetic energy is maximum. This demonstrates energy conservation, where energy is transferred between forms but total energy remains constant.

Question 1: Explain how gravitational potential energy is utilised in hydroelectric power stations.

Answer: In hydroelectric power stations, water is stored at a height, giving it GPE. When released, the water falls and converts GPE into kinetic energy, which drives turbines to generate electricity.

Question 2: Identify two safety precautions when lifting heavy objects to prevent accidents related to GPE.

Answer: Use proper lifting equipment and techniques, and ensure the area is clear of bystanders to prevent injury if the object is dropped.