This exam tips covers Exam Tips for Kinetic Energy within Kinetic Energy for GCSE Physics. Revise Kinetic Energy in Energy for GCSE Physics with 15 exam-style questions and 30 flashcards. This topic appears regularly enough that it should still be part of a steady revision cycle. It is section 14 of 15 in this topic. Treat this as a marking guide for what examiners are looking for, not just a fact list.
💡 Exam Tips for Kinetic Energy
🎯 Common Question Types:
- Calculate KE given mass and speed (1-2 marks)
- Find speed given KE and mass — remember to square root! (2-3 marks)
- Explain why faster = more dangerous (2-3 marks — must reference v²)
- Use KE = GPE to find speed after falling (3-4 marks)
📝 Key Command Words:
- Calculate: Show the equation, substitution, and answer with units
- Explain: Reference the v² relationship, not just state a fact
- Describe: Name what happens to KE when speed changes
⚠️ Common Mistakes to Avoid:
- Forgetting the ½ — will double your answer
- Forgetting to square v — will make your answer far too small
- Using grams instead of kg — convert first! (g ÷ 1000 = kg)
- Forgetting to square root when finding v — v² is not v!
Quick Check: A car triples its speed. By what factor does its kinetic energy increase?
The kinetic energy increases by a factor of 9 (= 3²). Because KE ∝ v², tripling v multiplies KE by 3² = 9.
Practice questions for Kinetic Energy
Which of the following objects has kinetic energy stored in its kinetic energy store?
A car travels at 20 m/s. The driver then doubles their speed to 40 m/s. Explain what happens to the kinetic energy of the car and by what factor it changes.