Definition: Impulse is the change in momentum of an object, which equals force ร time.
Key relationships:
- Impulse = Force ร time (F ร t) โ measured in N s
- Impulse = Change in momentum (ฮp = mฮv) โ measured in kg m/s
- 1 N s = 1 kg m/s (same unit, different names)
The crucial insight:
- For a given momentum change, increasing time decreases force
- F = ฮp / t โ longer time = smaller force
- This is why safety features work!
This key facts covers Understanding Impulse 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 2 of 7 in this topic. Use this key facts to connect the idea to the wider topic before moving on to questions and flashcards.
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 = Change in momentum (ฮp = mฮv) โ measured in kg m/s
Understanding Impulse
Impulse = Force ร time (F ร t) โ measured in N s