Simulation - Rotational Motion

The Basics of Rotational Motion

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Adjust the sliders to see:
  • how long it takes for the object to go around the circle once (period);
  • how many revolutions the object can complete in one second (frequency);
  • how many radians the object can cover per second (angular velocity).


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Drag the seesaw to change the angle.
The force can be adjusted by dragging its tip, and it can be moved by dragging its tail.
Calculations will appear here.

Moment of Inertia

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Drag the objects to different location and use the sliders to adjust their mass.
Calculations will appear here.

Conservation of Angular Momentum

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Both objects have mass \(m=1kg\) and are separated from the center by distance \(r\). Adjust \(r\) to see how the angular velocity changes, while the total angular momentu stays the same (conservation of angular momentum), obeying \(L = I \omega\).
Note \(I = 2 m r^2\), where the factor of 2 comes from the fact that there are 2 masses on the bar, with each mass contributing \(I_{one\ mass} = m r^2\).
Calculations will appear here.

Rolling Down an Incline

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Drag on the surface of the incline to change the angle.
The length of the track is \(20m\). The mass of each object is \(1kg\).
\(I_{disk} = \frac{1}{2} m r^2, I_{ring} = m r^2 \).


Work out the energy of each object at the bottom.
Can you explain why the block arrives at the bottom first, followed by the disc and then the ring?