Think you’ve got your head wrapped around Energy and Momentum? Put your knowledge to
the test. Good luck — the Stickman is counting on you!
Q. Which of the following quantities is conserved in an inelastic collision?
Kinetic energy
Potential energy
Total mechanical energy
Momentum
Speed
Q. How much momentum does a 5 kg ball have right before it hits the ground if it is dropped from 3 m in the air? Assume g = 9.81 m/s2.
7.67 kg⋅m/s
27.1 kg⋅m/s
38.4 kg⋅m/s
147 kg⋅m/s
241 kg⋅m/s
Q. A 60 kg diver is able to leap 2 m into the air off of a springboard. The board flexes and is in contact with the diver for 1.5 s before he jumps. How much force does the board provide to the diver?
120 N
250 N
376 N
883 N
1177 N
Q. Which of the following statements is true about conservative forces?
Conservative forces usually act based on an object's position.
Conservative forces can add energy to a system.
Conservative forces can remove energy from a system.
Conservative forces can both add energy to or remove energy from a system.
Conservative forces can create heat and sound.
Q. A 3500 kg howitzer cannon can fire 50 kg artillery shells at 700 m/s. Recoil from the shot will send the gun flying backwards—but how far backwards will the gun travel after each shot if it is placed on a hydraulic track that can provide 90,000 N of retarding force?
0.028 m
1.94 m
10.0 m
25.7 m
48.6 m
Q. A 400 kg roller coaster car is towed up a 35 m tall hill and then drops down a 60º incline. What is its speed at the bottom of the hill if friction is not neglected? The coefficient of friction between the coaster's wheels and the track is 0.3.
21.2 m/s
21.9 m/s
23.8 m/s
24.2 m/s
26.2 m/s
Q. How far does the center of mass of an 1800 kg pickup truck move when 800 kg of cargo is loaded into the bed, centered 1.5 m to the right of the pickup's original center of mass?
0.46 m
0.67 m
1.03 m
1.24 m
1.50 m
Q. Missile defense in the mighty Kingdom of Candyland is accomplished by a spring-loaded gumdrop cannon that fires gumdrops straight up, impacting candy cane missiles from the Democratic Goblin's Republic of Goblandia. A gumdrop weighs 0.5 kg and must strike the candy canes, which cruise at an altitude of 80 m, with 30 kg⋅m/s of momentum in order to ensure their destruction. If the spring in the gumdrop cannon has a stiffness constant of 1000 N/m, how far must the Marshmallow Knights compress the cannon in order to keep Candyland safe? (Candyland, of course, has sophisticated targeting computers. Aiming is not an issue.)
0.89 m
0.92 m
1.30 m
1.34 m
1.61 m
Q. How fast can the 7500 W motor on a chain lift bring a 500 kg roller coaster car up a hill tall enough to give the car a speed of 20 m/s at the bottom of the drop?
0.075 s
1.529 s
13.08 s
13.33 s
375.0 s
Q. A 3 kg block is sliding on a table at 6 m/s. It travels 1.5 m before it collides elastically with a second block, which weighs 5 kg and is at rest. The coefficient of friction between both blocks and the table is 0.2. How far does the second block travel before it comes to rest again?
0.48 m
4.32 m
5.16 m
11.05 m
11.99 m