An object's velocity vector points 135 degrees northwest. What is the direction of the momentum?
The momentum and velocity have the same direction, thus the momentum vector also has a direction of 135 degrees northwest.
100
Under what conditions can a compact car have the same momentum as a larger, heavier car?
The smaller car would have to be traveling faster.
100
Under what conditions is momentum conserved?
When the sum of the outside forces is zero.
100
Why did the eggs dropped onto the bed sheet not break?
Their momentum was absorbed over a long period of time, thus the impulse force was low.
200
What is the equation for momentum?
p = mv (p and v are vectors)
200
A golf ball and a lump of clay are both thrown at a wall. They each have the same mass and are thrown at the same velocity, and they each stop dead when they hit the wall. On which object does the wall exert the most impulse?
Impulse is defined as the change in momentum. This is the same for both. (Not to be confused with the Force).
200
Under what conditions is angular momentum conserved?
When the sum of the torques on a system is zero.
200
How many eggs did Andrew break during Experiment 9.1?
Seven.
300
Which of the following is not a valid unit for momentum?
kg*m/sec2 , g*km/min , ft*slug/hr
kg*m/sec2 Any set of units that represent a mass times a velocity are valid, but this one has sec2 on the bottom.
300
A golf ball and a lump of clay are both thrown at a wall. Which one experiences the most force?
Since the golf ball is in contact for a shorter time, the Force must be higher (since the change in momentum is the same).
300
A marksman fires two guns. they each have the same mass and fire their bullets at roughly the same velocities. The first fires heavy bullets, while the second fires lighter ones. Which gun has the greater recoil velocity?
The one firing the heavier bullets.
300
What two equations can be used to understand how a Newton's Cradle works?
Kinetic Energy and Momentum
400
What is the actual (full) form of Newton's Second Law?
F = dp/dt
400
How did we derive the "impulse" equation?
We took Newton's Second Law, used the momentum form, and solved for delta p.
400
How does a rocket work?
Fuel is ejected from the rocket. This fuel has momentum. In order for momentum to be conserved, the rocket must travel in the opposite direction.
400
Why would a store-bought Newton's Cradle work better than the ones we built for Experiment 9.2?
Heavier balls, lighter string, two strings holding each ball.