1. Oct 27, 2016

FallenApple

So I noticed something about problems. I see the number 2/3 or 3/2 a lot. For example, the height masses lose contact with sphere. Ladder losing contact with wall etc. Or 3/2 for the height above a rolling cue ball to strike for it to stop etc. And I notice the number 2/5 and 5/2 a lot as well. For example, the minimum height to make around the loop de loop.

Is there something more fundamental going on here?

2. Oct 27, 2016

Staff: Mentor

I think this is a result of teachers designing problems with simple exact solutions. This is not unlike the use of 30-60-90 or 45-45-90 triangles in trig or Pythagorean triplets i.e. 3-4-5 right triangles when teaching the Pythagorean theorem.

3. Oct 27, 2016

robphy

4. Oct 28, 2016

A.T.

I have noticed lots of 1/2 popping up recently. There must be a nest somewhere.

5. Oct 28, 2016

vanhees71

The worst are factors of powers of $2 \pi$. They tend to be missing or appear to often in formulae. In this case you can trace it to Fourier as the culprit. LOL.

6. Oct 28, 2016

A.T.

Use τ.

7. Oct 28, 2016

vanhees71

$\tau$?

8. Oct 28, 2016