This exam tips covers Exam Tips for Gravitational Potential Energy within Gravitational Potential Energy for GCSE Physics. Revise Gravitational Potential Energy in Energy for GCSE Physics with 15 exam-style questions and 6 flashcards. This is a high-frequency topic, so it is worth revising until the explanation feels precise and repeatable. It is section 15 of 16 in this topic. Treat this as a marking guide for what examiners are looking for, not just a fact list.
💡 Exam Tips for Gravitational Potential Energy
🎯 Common Question Types:
- Calculate GPE given mass and height (1-2 marks)
- Find the speed at the bottom of a fall using GPE = KE (3-4 marks)
- Explain why a roller coaster has maximum speed at the bottom (2-3 marks)
- Compare GPE on different planets (2-3 marks — change the g value)
📝 Key Command Words:
- Calculate: Show E_p = mgh with values substituted and include units
- Explain: Reference GPE converting to KE as height decreases
- Compare: Show how changing g or h or m affects the GPE value
⚠️ Common Mistakes to Avoid:
- Using distance along slope instead of vertical height — only vertical h counts!
- Using wrong g value — use 10 N/kg unless told otherwise
- Forgetting unit conversions — mass in kg, height in m
- Not recognising conservation problems — if GPE converts to KE, set them equal
Quick Check: A 3 kg ball is dropped from a height of 20 m. What is its speed just before it hits the ground? (g = 10 N/kg, ignore air resistance)
GPE = mgh = 3 × 10 × 20 = 600 J. All converts to KE: ½mv² = 600 J → ½ × 3 × v² = 600 → v² = 400 → v = 20 m/s.
Practice questions for Gravitational Potential Energy
What is the value of gravitational field strength (g) on Earth?
Explain how gravitational potential energy is related to an object's mass and height. Refer to the equation Ep = mgh in your answer.