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This all counts as 1 question in class because it's supposed tobe already known. So please answer all of them. I just want to besure I'm right.

Question 1

Which of the following statements are true regarding momentum?Check all that apply.

The total momentum of an isolated system is conserved, butinternal forces can change the total momentum of the system

pinitial = (m1v1)i + (m2v2)i + (m3v3)i + …

pfinal = (m1v1)f + (m2v2)f + (m3v3)f + …

The x and y components of momentum are independentlyconserved

Total momentum is conserved, but angular momentum is not.

A figure skater spins faster when she draws in her arms becausetorque is conserved.

Momentum points in the same direction as the applied force

Angular momentum points in the same direction as the netapplied torque

Momentum points in the same direction as the velocity of theobject

Question 2

A bug and the windshield of a moving car collide. Indicate whichof the following statements are TRUE. (Select all that apply)

The impulse on the bug and the car are the same magnitude

The impact force on the bug and the car are the samemagnitude

The change in velocity of the bug and the car are the same

The change in momentum of the bug and the car are the samemagnitude

None of the above

Question 3

A running thief is being chased by the police, and he jumps on astationary skateboard hoping he will be able to go faster. That isa good idea because:

Momentum is conserved, and thus his velocity will increase whenhe jumps on the skateboard (which has a smaller mass).

Angular momentum is conserved, so that the wheels on theskateboard can spin much faster than his feet can run on theground.

Momentum is conserved, and since his mass combined with theskateboard is larger, he can go faster.

Momentum is conserved, which means he will go a little sloweron the skate, but will look cooler as he does so.

Question 4

Which of these are forms of energy? Check all that apply:

Kinetic Energy

Gravitational Potential Energy

Spring Potential Energy

Friction Energy

Thermal Energy

Inertial Energy

None of the above

Question 5

Bob pushes a 1-meter wide bookcase with a force of 100 N for 10seconds, but the bookcase does not move due to friction. How muchwork has Bob done?

100 Nm

1000 Nm

10 Nm

None of the above

Question 6

Which of the following are units of Work?

kg / s2

N m

Joules

Calories

Degrees

(kg m / s)2 / kg

None of the above

Question 7

If an object has kinetic energy, then it also must have...(check all that apply)

Speed

Impulse

Acceleration

Force

None of the above

Question 8

When an object is lifted 10 meters, it gains a certain amount ofpotential energy. If the same object is lifted 20 meters, itspotential energy is:

Less

The same

Twice as much

Four times as much

None of the above

Question 9

Which of the following statements are true? Check all thatapply:

Work is the what you get when a force acts over a certaindistance. Therefore, without distance or force there would be nowork.

Work and Distance are related because force is acted over along distance.

Without work you do not have force.

Energy is the ability to do work or make work, and work is notdone without it.

Energy causes a change, and work is needed for energy toexist.

Energy is the ability to do work or cause a change, and work isthe transfer of energy.

Kinetic energy is the energy of motion, and potential energy isstored energy.

Potential energy is the energy of weight, and kinetic energy isthe energy of nuclear atoms.

None of the above