Momentum Flashcards
(8 cards)
What is momentum ?
Mass multiplied by velocity
If a force acts on a body then momentum will change
Newton’s second law, we can see that the force is proportional to the rate of change of momentum with time
What is the impulse ?
The product of the force and the time
The importance of impulse
When landing after jumping from a height a person bends their knees to increase the time over which they stop and hence reduce the force
Cars are built with crumple cones so that an impact they will be brought to a stop over a longer period giving a smaller force
How is impulse represented ?
The area under a force time graph
What is the principle of conservation of momentum ?
Total mv before all bodies is equal to the total mv after all bodies
If no external forces acting then the total Chang in mv of system is 0
Total momentum of system will be constant
What is conserved and what isn’t in a collision ?
Total p is always conserved but the total KE isn’t always conserved
What is an elastic collision ?
If the total KE of moving bodies remains constant
What is an inelastic collision ?
When total KE of moving bodies is not conserved
