A simple and convincing demonstration of the intermediate axis theorem. Consider an object (a tennis racquet in this case) with three unequal principle moments of inertia. If the racquet is set into rotation about either the axis of greatest...
A suspended hula hoop has the same period of oscillation as a pendulum whose length is equal to the diameter of the hoop.
The parallel-axis theorem allows us to readily deduce the rotational inertia of a hoop about an axis...
One can show that the period of oscillation of an object doesn't change for different suspension points, as long as they're the same distance from the COM. This is consistent with what the parallel-axis theorem tells us about the moment of...
A very large cable spool (or smaller version) is made to roll in either direction or slide, depending on the angle of pull; action of a torque.
Depending upon the angle of applied force, a yo-yo can be made to roll forwards, backwards or...
An object rolling down a hill acquires both translational and rotational kinetic energy. One must take the rotational kinetic energy into account when calculating the object's velocity at the bottom of the hill
The illustration depicts the...
Allow a board to rotate under the force of gravity and the free end will accelerate at a rate greater than g. Relation between angular acceleration and linear acceleration seems to give free-fall paradox.
If a board, held in a...
The motion (or lack of motion) of the suspension point of an object is observed when the object is struck a blow.
The center of percussion (COP) is the place on a bat or racket where it may be struck without causing reaction at the point of...
