๐ฏ Common Question Types:
- Calculate impulse from force and time (2 marks)
- Calculate average force during a collision (2-3 marks)
- Explain how crumple zones / airbags reduce force (3 marks)
- Distinguish elastic from inelastic collision (2 marks)
- Interpret area under a force-time graph (2 marks)
๐ Key Command Words:
- Calculate: Show impulse = F ร t = ฮp; include units (N s or kg m/s)
- Explain: Use "increasing time โ decreasing force" chain of reasoning
- Suggest: Apply the physics principle to an unfamiliar context
- State: "Momentum is always conserved; kinetic energy is only conserved in elastic collisions"
โ ๏ธ Common Mistakes to Avoid:
- Confusing impulse (N s) and momentum (kg m/s) โ they are numerically equal but described differently
- Forgetting to include direction in momentum change calculations
- Saying kinetic energy is conserved in all collisions โ it is ONLY conserved in elastic collisions
- Misreading force-time graphs โ area = impulse, NOT force or velocity
This exam tips covers Exam Tips โ Impulse and Collisions within Impulse & Collisions for GCSE Physics. Revise Impulse & Collisions in Forces for GCSE Physics with 13 exam-style questions and 10 flashcards. Use this page as part of a wider topic revision path rather than treating it as an isolated fact. It is section 5 of 7 in this topic. Treat this as a marking guide for what examiners are looking for, not just a fact list.
Practice questions for Impulse & Collisions
Which equation correctly defines impulse?
Explain how an airbag reduces the risk of injury to a driver in a collision.
Quick recall flashcards
Understanding Impulse
Impulse = Force ร time (F ร t) โ measured in N s
Understanding Impulse
Impulse = Change in momentum (ฮp = mฮv) โ measured in kg m/s