Energy and Momentum of Rotating Systems unit test
A test on this unit alone, marked as a percentage and a letter grade — for the test your class is actually sitting, rather than for May. Answer everything, then submit once: seeing the answer to question 3 before attempting question 4 makes the final percentage meaningless.
Rolling race
K = L²/2I
Racing shapes down a ramp
Angular momentum
Where to strike a pivoted rod for maximum effect
A particle moving in a straight line has angular momentum
Angular momentum in orbits
Rotational kinetic energy
A sliding block beats every roller
Comparing linear and rotational analogues
Angular momentum of a particle
Rotational work and power
Short answer 1. Define or explain: The spinning skater
3 ptsShort answer 2. Define or explain: A rolling object carries two kinetic energies
3 ptsShort answer 3. Define or explain: Rolling down a ramp by energy
3 ptsShort answer 4. Define or explain: Work done by a torque
3 ptsFree response
7 ptsA solid disk and a hollow hoop have the same mass M and radius R. Both are released from rest at the top of an incline of height h and roll without slipping to the bottom. (a) Explain, without calculation, why both objects arrive with less translational speed than a frictionless sliding block released from the same height. (b) Derive an expression for the translational speed at the bottom in terms of M, R, h, g and the moment of inertia I. (c) Use your expression to determine which object arrives first, and justify why the result does not depend on M or R.
Explain, without calculation, why both objects arrive with less translational speed than a frictionless sliding block released from the same height.
Derive an expression for the translational speed at the bottom in terms of M, R, h, g and the moment of inertia I.
Use your expression to determine which object arrives first, and justify why the result does not depend on M or R.