F = ma
1Average velocity of a bead going around a hoop *
2Direction of acceleration at the bottom of a pendulum swing *
3Vertical velocity graph of a bouncing soccer ball *
4Work to drag a box slowly up an incline *
5Acceleration of masses in a pulley system *
6Height difference in a swinging conical pendulum *
7Minimum friction to keep stacked boxes from sliding *
8Speed ratio of two orbiting stars *
9What loses energy as a balloon rises to the ceiling *
10Aiming angle for an arrow to hit a target *
11Maximum height for a straight-up throw versus a sideways one *
12Tension change in a string after cutting another *
13Sliding versus lifting off for a box pushed at an angle *
14Weight fraction on one leg of a three-rod stand *
15Enclosed mass from a galaxy's rotation curve *
16Timing of a pendulum bouncing off a wall *
17Ranking moments of inertia of three physical pendulums *
18Ranking measured weights of bagged rocks in water *
19Uncertainty in g from a pendulum experiment *
20Velocity components curve of a swinging pendulum *
21Return time of a mass sliding inside a ring *
22Ranking effective spring constants from three spring combinations *
23Distance ratio from a parallax angle shift *
24Speed change bouncing off an oscillating plate *
25Horizontal distance after a ski jump ramp *
USAPhO
1A1. Circus Act
2A2. Time is a Flat Circle
3A3. The Motive Power of Ice
4B1. Electric Roulette
5B2. Fast and Furious
6B3. Starry Messengers