Momentum Flashcards
We claim that momentum is conserved yet most moving objects eventually slow and stop
Momentum is only conserved on a closed system (not closed object) so with the car stopping the momentum is being transferred to the earth from the car but the velocity is so small to us it’s is nonexistent
When you release an inflated but untied balloon why does it fly across the room
The gas and the balloon is together in a closed system so the momentum is conserved and the momentum of the gas is escaping and the ballon has to meet with the momentum from the opposite direction
When a person jumps from a tree to a ground what happened tothe momentum of. The person upon striking the ground
The momentum is transferred to the earth but it’s so small it’s nonexistent
How can a rocket change direction when it is far out in space and essentially in a vacuum
It’s like the balloon the rocket and the gas are in a closed system by releasing the gas in the opposite way from where they want to go
Why can a batter hit a pitched baseball further than a ball tossed up in the air by the batter
There is no horizonatal velocity for the ball tossed
Is it possible for an object to receive a larger impulse from a small force than a large force
Yes if the time is longer so if the product is bigger and small force can have a larger impulse because impulse is force and time
Cars used to be built rigid as possible to withstand a collision today though cars are designed to have crumple zones that collapse upon impact what is the advantage of this new design
The longer the collision the less the force and impact
Two cars with same mass and velocity have the same momentum yes or no
No unless same direction also because momentum is a vector
A white cue ball travels across a pool table and collides with a stationary 8 ball the two balls have equal mass after the collision the cue ball is at rest what is everything you know about this collision, what If after the collision each ball has some of the original momentum
It was a head on collision not at an angle and it could be elastic collision, they must be at an angle
Two trains cars that look the same collide one was originally at rest they stick together and move off at more than half the original velocity of the moving train car, what can you sag about the mass contents of the two trains and everything you know about this collisions, and what if it moves off at the half the original velocity and ,over lff at less than half the original velocity
V greater than v initial/2 the second car is led sheave and has less mass than the first, v=v initial/2 it’s equal mass, v
You are sitting at a baseball game when a foul ball comes in your direction, you catch it barehanded in order to catch it safely should you move your hands towards the ball hold them still or move them in teh same direction as the moving ball
Move them the same direction as the ball because the longer the time for the collision the less teh force necessary to change the momentum
Explain the difference between impact and impulse as they relate to momentum
Impulse is the force and the time while impact is just the force
Explain the difference between elastic and in elastic collision
In in elastic kinetic energy is not conserved and in elastic collisions kinetic energy is conserves both momentum is conserve
A perfect in elastic vs a regular in elastic collision
Perfect the two objects stick together and in a regular only kinetic energy is lost and not conserved nothing sticks together KE initial>KE total in in elastic regular
What happens to the kinetic energy in elastic collision
KE initial = KE total
