CH. 6 HW Part B

What is the ratio of speeds of the carts when the spring is released?

v2m/vm= 0.5

At what speed does the wreckage move if one car was driving north and one east?

v= 13 m/s

In which is momentum conserved: an elastic collision or an inelastic collision? a) momentum is conserved in elastic and inelastic collisions b) momentum is conserved only in inelastic collisions c) momentum is conserved only in elastic collisions d) momentum is conserved in neither elastic nor inelastic collisions

a) momentum is conserved in elastic and inelastic collisions

Railroad car A rolls at a certain speed and makes a perfectly elastic collision with car B of the same mass. After the collision, car A is observed to be at rest. How does the speed of car B compare with the initial speed of car A? a) the speed of car B is equal to the initial speed of A b) the speed of car B is half the initial speed of car A c) the speed is car B is zero d) the speed of car B is twice the initial speed of car A

a) the speed of car B is equal to the initial speed of A

If the equally massive cars of the preceding question stick together after colliding inelastically, how does their speed after the collision compare with the initial speed of car A? a) their speed is half the initial speed of car A b) their speed is equal to the initial speed of car A c) their speed is zero d) their speed is twice the initial speed of car A

a) their speed is half the initial of car A

A 5000-kg freight car moving at 2 m/s collides with a 10,000-kg freight car at rest. They couple upon collision and move away at a) 1/3 m/s b) 2/3 m/s c) 1 m/s d) 2 m/s

b) 2/3 m/s

Which undergoes the greatest change in momentum (if all of the baseballs have the same speed just before being caught and just after being thrown)? a) a baseball that is caught b) a baseball that is caught and then thrown back c) a baseball that bounces out of the glove straight down d) a baseball that bounces out the glove straight up

b) a baseball that is caught and then thrown back

What does it mean to say that momentum is conserved? a) it means the net momentum is zero b) it means momentum is zero c) it means momentum does not change d) it means the change in momentum is equal to the impulse

c) it means momentum does not change

In what direction and at what speed does the wreckage move if one car was driving north and one south. a) the wreckage after collision is moving at the speed 9.5 m/s to the south b) the wreckage after collision is moving at the speed 9.5 m/s to the north c) the wreckage after collision is motionless d) the wreckage after collision is moving at the speed 19 m/s to the north

c) the wreckage after collision is motionless

Is it correct to say that, if no net impulse is exerted on a system, then no change in the momentum of the system will occur? a) sometimes b) no, never c) yes, always d) almost always

c) yes, always

A 1-kg glider and a 2-kg glider both slide toward each other at 1 m/s on an air track. They collide and stick. The combined mass moves at a) 0 m/s b) 1.5 m/s c) 1/6 m/s d) 1/3 m/s e) 1/2 m/s

d) 1/3 m/s

In what direction does the wreckage move if one car was driving north and one east (as shown in the following figure)? a) to the west b) to the northwest c) to the east d) to the northeast e) to the north f) to the south

d) to the northeast