Collisions, explosions and impulse Flashcards
Equation of momentum
p = m v
Momentum can have a positive and negative value as it’s is a…
Vector quantity
State the definition of the law of conservation of momentum:
Total momentum before a collision equals total momentum after a collision in the absence of external forces
Total momentum before = total momentum after (equation)
m1v1 + m2v2 = m3v3
Elastic collision definition?
Total kinetic energy before a collision is equal to the total kinetic energy after a collision
Inelastic collision definition?
Total kinetic energy after a collision is less than the total kinetic energy before a collision
What is change in momentum equal to?
Impulse (Ft)
What is the area under a force-time graph equal to?
The impulse
When calculating the impulse time units must be in…
Seconds
On a force time graph if a material is softer it would result in a _____ time of contact and a _______ maximum force.
Longer, smaller
Explain the job of safety features in cars
Their job is to increase the time of contact which reduces the force (injury) to occupants.
