# Would there be any way to produce a force that follows a sinosoidal law? [closed]

What would produce a force that depends on the sine or cosine of the distance?

## closed as off-topic by Serban Tanasa, AndreiROM, Frostfyre, DaaaahWhoosh, James♦Dec 8 '15 at 16:20

This question appears to be off-topic. The users who voted to close gave this specific reason:

• "This question does not appear to be about worldbuilding, within the scope defined in the help center." – Serban Tanasa, AndreiROM, Frostfyre, DaaaahWhoosh, James
If this question can be reworded to fit the rules in the help center, please edit the question.

• try physics stack exchange... also are you looking for a force that push and pull object repetitively? – user6760 Dec 8 '15 at 6:26
• In other words, a force where $F\propto\sin r$? – HDE 226868 Dec 8 '15 at 16:52

## 3 Answers

Yes. A simple pendulum has a force proportional to $\sin \theta$, although a small-angle approximation is generally used, wherein $\theta$ is used instead. One might object that $\theta$ is not a length. I suspect that a "truly" sinusoidal force dependent on linear Euclidean distance might be difficult.

• I recall a type of cam that makes a pendulum work exactly with θ rather than just being a small-angle approximation. Depending on what the OP means, perhaps a cam can do whatever is needed. – JDługosz Dec 8 '15 at 11:57

Any standing wave will do the trick.

• A standing wave depends on more than just the distance. – Samuel Dec 8 '15 at 5:55

How about this: A pendulum will have a force based on the tilt, which is related to the sin of the angle. Allow a weight to work in the manner. Then, using mechanical computing principles, arrange for a light-weight cursor to ride in a track that moves horizontally only, in a straight line. The weight rises behind the front panel, and the visible cursor shows the horizontal component only.

When you move the cursor, using a hand-held spring to tug it along the track, you will measure the restoring force to be proportional to the sin of the distance where full extension on the track is 1 unit.