Problems

#	Title	Difficulty	Solved	Accept.
124	Centrifugal Failure+20Med.	Med.	1	—
1	Biaxial Plate PendulumHard	Hard	5	45.5%
2	Springy Hoop PendulumMed.	Med.	7	30.4%
3	Squirt Gun EnergyMed.	Med.	8	80.0%
4	Work in a Moving FrameEasy	Easy	22	44.0%
5	Trailing SledHard	Hard	6	54.5%
6	Piezometer Elevation DropMed.	Med.	4	57.1%
7	Sag and LiftMed.	Med.	2	28.6%
8	Horizontal BounceHard	Hard	7	24.1%
9	Spring Lift-OffMed.	Med.	6	85.7%
10	Centrifugal BuoyancyMed.	Med.	3	100.0%
11	Sweeping Satellite in Dust CloudMed.	Med.	3	100.0%
12	Ambiguous InelasticityEasy	Easy	9	90.0%
13	Rolling on a Moving RampMed.	Med.	4	100.0%
14	Energy of a Robotic ArmMed.	Med.	4	66.7%
15	Center of Mass ShiftMed.	Med.	2	50.0%
16	Reinforced TripodMed.	Med.	1	—
17	Rolling Cylinder on a SpringMed.	Med.	5	100.0%
18	Center of Percussion of a DumbbellMed.	Med.	3	60.0%
19	Elevator OscillatorsMed.	Med.	5	83.3%
20	Double Conical PendulumMed.	Med.	3	75.0%
21	Rolling to Slipping TransitionMed.	Med.	2	66.7%
22	Oscillator in a Shrinking CavityMed.	Med.	3	100.0%
23	Force on a Shifting AxisMed.	Med.	3	100.0%
24	Adiabatic Mass LossMed.	Med.	5	100.0%
25	Compound-Wheel CascadeMed.	Med.	0	—
26	The Hexagonal Space Station IMed.	Med.	8	29.3%
27	The Hexagonal Space Station IIHard	Hard	5	46.7%
28	The Hexagonal Space Station IIIHard	Hard	2	100.0%
29	Coincident FrequenciesMed.	Med.	3	37.5%
30	3D Ring FrictionMed.	Med.	3	60.0%
31	Sequential Frictional StoppingMed.	Med.	4	66.7%
32	Coupled Friction on SledEasy	Easy	6	85.7%
33	Momentum Flux TensionMed.	Med.	3	75.0%
34	Dust Drag on HemispheresMed.	Med.	2	100.0%
35	Hidden Mass Spring PendulumMed.	Med.	2	40.0%
36	Density Error PropagationEasy	Easy	5	62.5%
37	Sandwiched Slipping BlocksMed.	Med.	3	42.9%
38	The PH-SL0 Droid IMed.	Med.	4	40.0%
39	The PH-SL0 Droid IIHard	Hard	2	50.0%
40	The PH-SL0 Droid IIIHard	Hard	2	100.0%
41	Restricted Collision StatesMed.	Med.	4	80.0%
42	Turntable String TensionMed.	Med.	4	80.0%
43	Randomly Sampled OrbitMed.	Med.	3	100.0%
44	Free Rod CollisionMed.	Med.	4	44.4%
45	Heavy Hoop PendulumMed.	Med.	6	100.0%
46	Frame-Dependent Launch EnergyEasy	Easy	4	100.0%
47	Slipping Stack AccelerationMed.	Med.	4	100.0%
48	Friction Over a Curved PathMed.	Med.	5	100.0%
49	Impulsive FrictionMed.	Med.	5	100.0%
50	Tapered Capillary TubeMed.	Med.	8	100.0%
51	Turntable Doppler SpectrumMed.	Med.	5	62.5%
52	Near-Side Tidal WeightMed.	Med.	2	33.3%
53	Bouncing Particle and Massive BlockHard	Hard	4	66.7%
54	Constant Power ScalingEasy	Easy	6	46.2%
55	Cradled DescentHard	Hard	1	—
56	The Hidden HorizontalEasy	Easy	0	—
57	Twin CavitiesMed.	Med.	0	—
58	Pegged PendulumMed.	Med.	0	—
59	Critical Speed LimitMed.	Med.	1	33.3%
60	Cascading Slip ThresholdsHard	Hard	0	—
61	Threshold to TumbleMed.	Med.	0	—
62	Compounded Spring StiffnessMed.	Med.	0	—
63	Quarter-Period RendezvousEasy	Easy	0	—
64	Pumping the PendulumMed.	Med.	0	—
65	Maximum LiftMed.	Med.	0	—
66	After LiftoffEasy	Easy	2	100.0%
67	Slipping ShellMed.	Med.	0	—
68	Calibrating by PeriodMed.	Med.	0	—
69	Cascading DisadvantageMed.	Med.	0	—
70	Layered WindMed.	Med.	1	—
71	Equal-Time Dead ZoneMed.	Med.	0	—
72	Hidden GaussianEasy	Easy	1	—
73	Tilted Free FallMed.	Med.	1	—
74	Coalescence CeilingMed.	Med.	0	—
75	Free Ballistic CaptureMed.	Med.	0	—
76	Effective AnchorMed.	Med.	0	—
77	Lifting a Submerged ConeMed.	Med.	0	—
78	The Yielding WedgeMed.	Med.	1	—
79	Decay InvariantsMed.	Med.	1	—
80	Pumping the SwingHard	Hard	2	66.7%
81	Compound AccelerationMed.	Med.	1	—
82	Triangular JointsMed.	Med.	0	—
83	Hexagonal PivotMed.	Med.	0	—
84	Lunar-Gravity ParabolaEasy	Easy	1	—
85	Rigid Rod Conical PendulumMed.	Med.	0	—
86	Successive ReboundMed.	Med.	0	—
87	Reluctant AnvilHard	Hard	1	—
88	Subterranean PerihelionMed.	Med.	0	—
89	Apsides After ImpulseMed.	Med.	1	—
90	Torsion Disk ReboundMed.	Med.	0	—
91	Threshold of MotionEasy	Easy	0	—
92	Whirling Bowstring StabilityMed.	Med.	0	—
93	Inverted CascadeMed.	Med.	0	—
94	Floater's TollMed.	Med.	0	—
95	Pendulum Sweet SpotMed.	Med.	0	—
96	Background-Limited CountingMed.	Med.	0	—
97	Capped RangeMed.	Med.	1	—
98	Climbing in PlaceMed.	Med.	0	—
99	Crosswise Frictional HeatingMed.	Med.	0	—
100	Trapped Rotational EnergyEasy	Easy	1	—
101	Asymptotic CruiseMed.	Med.	0	—
102	Pseudogravity DecayEasy	Easy	0	—
103	Convection on a ScaleMed.	Med.	0	—
104	Asymptotic StoppingMed.	Med.	1	—
105	Coriolis CancellationHard	Hard	0	—
106	Diving Board FailureMed.	Med.	0	—
107	Keplerian Catch-UpMed.	Med.	0	—
108	Comparing Mint BatchesEasy	Easy	0	—
109	Common Rim SpeedEasy	Easy	0	—
110	Decoupled DescentEasy	Easy	1	—
111	Traction-Limited LapMed.	Med.	1	—
112	Galilean Energy AccountingMed.	Med.	0	—
113	Power-Limited MicroswimmerEasy	Easy	0	—
114	Synodic TerminatorMed.	Med.	0	—
115	Climbing the WellMed.	Med.	2	100.0%
116	Orbital ShrapnelHard	Hard	1	—
117	Crossed Spring EquilibriumMed.	Med.	0	—
118	Rolling Oscillator on a Slippable PlatformMed.	Med.	0	—
119	Fountain Apparent WeightMed.	Med.	2	100.0%
120	Closing the LoopHard	Hard	3	100.0%
121	Where the Heat GoesMed.	Med.	1	50.0%
122	Heavy-Planet DrillMed.	Med.	0	—
123	Spinning ManifoldMed.	Med.	2	66.7%
125	Fluctuation-Induced BoostHard	Hard	0	—