Collisions, Momentum and Energy Flashcards
What is the symbol of momentum?
p
What is the unit of momentum?
Kg m s-1
What is the momentum of a stationary object?
0
State the law of conservation of Linear Momentum:
The total moments before a collision is equal to the total momentum after a collision in the absence of external forces
What is the equation that proves the law of conservation of linear momentum?
m1u1+m2u2=m1v1+m2v2
What are the 2 types of collision?
Elastic and inelastic
How do you know if a collision is elastic?
In an elastic collision kinetic energy is conserved
How do you know if a collision is inelastic?
In an inelastic collision kinetic energy is not conserved (it decreases)
What is the law of conservation of linear momentum also applicable to?
Explosions
What is it important to remember in collision questions?
- Momentum is a vector quantity so values can be positive or negative
- the direction objects are moving in (relates to above)
What is the symbol for impulse?
Ft
What is impulse?
The change in momentum of an object
When given a force time graph how do you calculate impulse?
The area under the graph
Why are cars fitted with crumple zones?
To increase the time of the collision and so reduce the size of the force on the car
State newtons 3rd law
For every action there is an equal but opposite reaction
