Impulse and Collisions
Impulse is the change in momentum caused by a force acting over time, which explains why crumple zones make cars safer.
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Impulse is the change in momentum caused by a force acting over time, which explains why crumple zones make cars safer.
- Impulse equals force times time
- Longer stopping time means smaller force
- Airbags increase collision time
🧠 Quick quiz
Three questions. Score 2 or more to complete the topic.
What is Impulse and Collisions?
Within Physics, which covers forces, energy, waves, electricity, magnetism, light and space explained through motion and experiments, this topic explains Impulse and Collisions. Physics topics explain how things move, push, heat up and carry energy, so each one here pairs a definition with a live model you can change.
Check that you can explain Impulse and Collisions in your own words and give one example from everyday life. If you can do that, you have understood the core idea.
Understanding Impulse and Collisions explains how the physical world behaves, from sport and transport to electricity and medicine.
Impulse and Collisions in detail
Impulse is the change in momentum, equal to force multiplied by the time it acts: FΔt = Δp. The same change in momentum can be achieved with a large force over a short time or a small force over a long time.
Safety features such as crumple zones, airbags and padded helmets increase the time of impact, reducing the force on the body. Catching a ball by moving your hands back follows the same idea. Collisions can be elastic, with kinetic energy conserved, or inelastic, where some energy is transferred to heat and sound.
How the interactive helps you understand Impulse and Collisions
Watch the force arrows in the interactive. Use any sliders or buttons it offers to change the values and see how the force arrows responds.
Before you change anything, predict the result. Then change one value at a time and check whether your prediction was right. This is a quick way to build a correct mental model of Impulse and Collisions.
Real-life uses and examples
- Answer “explain” questions by linking Impulse and Collisions to a clear cause and effect.
- Predict what a ball, car or circuit will do with Impulse and Collisions before you do the calculation.
- Explain everyday devices, such as brakes, lifts or chargers, using Impulse and Collisions.
Common mistakes to avoid
- Forgetting that some quantities, such as force or velocity, also have a direction.
- Mixing up Impulse and Collisions with a related quantity that has different units.
- Learning the definition without testing it. Use the quiz and the interactive to check that you can apply the idea.
Frequently asked questions about Impulse and Collisions
What is Impulse and Collisions?
Impulse is the change in momentum caused by a force acting over time, which explains why crumple zones make cars safer.
What are the most important points about Impulse and Collisions?
The main points are: Impulse equals force times time; Longer stopping time means smaller force; Airbags increase collision time.
Why is Impulse and Collisions useful?
Understanding Impulse and Collisions explains how the physical world behaves, from sport and transport to electricity and medicine.
How can I practise Impulse and Collisions?
Open the interactive at the top of this page and change the controls one at a time. Predict the result before each change, then take the three-question quiz. A score of two or more marks the topic as complete on this device.
Which topics are related to Impulse and Collisions?
Related topics in Physics include Kinetic Theory of Matter, Specific Heat Capacity, Convection.