Physics Help!?

Question

Why is more impulse delivered during a collision when bouncing occurs, than during one when it doesn't?

P.S. I'd appreciate if u'd give me a legit answer-don't put simple pointless ones like 'i don't know'. If u don't know, then common sense tells u don't answer.

Answer 1

Conservation of momentum is in play. Energy cannot be destroyed or created, however, when two objects collide inelastically (when there is less bounce or when they stick together), momentum is not concerved. Some is lost during the collision so that the impulse is smaller. In an elastic collision, where there is full "bounce" the objects lose no momentum so the impulse is greater. They can move of at a greater speed since no momentum is lost so the impulse is greater.

Key formulas for conservation of momentum are as follows:
kinetic energy= (mv^2)/2
Kinetic energy initial of all objects involved in the collision- KE final of all objects involved in the collision)
and momentum formulas are mv. For a collision, you simply make mv positive for movement to the right and - for movement to the left and set initial momentum of all objects equal to the finals.

Hope that helped!

Answer 2

There are elastic and inelastic collisions. More explicitly there are totally-elastic and totally inelastic and everything in between. In totally elastic collistions(where there's the most amount of bouncing) the total kinetic energy(impulse or energy of motion) of the two objects before the collision is the same as the total kinetic energy after the collistion. Stated another way, KE1_before + KE2_before = KE1_after + KE2_after. No energy of motion is lost.
In a collision that's partially or totally inelastic, some of the energy of motion gets absorbed by the collision. Some bouncing can occur in this case but it's not the maximum amount of bouncing. In a totally inelastic collision, no bouncing occurs. Throwing a piece of clay at another one and the clay sticks to the other piece is an example of a totally inelastic collision.
Almost all collisions between large objects(ones you can see) are at least partially inelastic. Even if there is bouncing some energy(impulse) gets absorbed by the material when it flexes during the collision. This is one reason a ball doesn't bounce to the same height as you dropped it from, some of the kinetic energy of the ball was absorbed by the bounce(collision with the earth)

Answer 3

When the objects bounce back towards where they came from they have a large change in momentum. m*v1 in one direction to m*v2 in the opposite direction. In a collision where they come to a stop, their change in momentum isn't as large. Impulse is directly related to change in momentum.

delta P = F*delta time

Answer 4

So much force is aplied that the impact doesn't absorb it all and the rest is reflected back. At the moment of impact, you have forward force which is immediately changed to reward force. This is what whiplash is.

Answer 5

it has something to do with matter and how long the collision is