Topic 5 Flashcards
Momentum
the quantity of motion an object has.
vector quantity.
Linear momentum formula
Mass x velocity
P = m x v
Conservation of linear momentum
momentum before collision = momentum after collision
“In the absence of external forces the total momentum of a system remains constant”
impulse definition
apply an impulse = to change the momentum of a system
Impulse formula
= force x time = ? N/s
Linear impulse = Ft = Ap = mvf - mvi
How to change impulse?
Change force, or change time force is applied
What is an impact
collision of two bodies, characterised by large forces being transmitted over a relatively short period of time
The outcome of a collision depends on:
momentum
nature of impact (elasticity)
what is elasticity
the ability of an object/body to return to its original shape after it has been deformed
Highly elastic object
returns to original shape quickly, velocity before collision is very similar to the velocity after collision
moderately elastic object
returns to original shape slowly
inelastic/plastic object
does not return to its original shape, velocity after collision is minimal/zero
what is the coefficient of restitution
its a measure of elasticity of a body/surface interaction
0 = low/plastic
1 = highly elastic
coefficient of restitution formula
= velocity after impact / velocity before impact
OR
= √height bounced / height dropped
4 factors impacting coefficient of restitution
- composition of ball, high pressure = high elasticity
- surface/striking element composition, high give = low rebound
- temperature, high temp = high elasticity
- velocity of impact, high velocity = low elasticity
