formula to convert rad to rev?

Question

I spent ten minutes googling and can't find it anywhere.

What is the formula to convert a rev to rad?

What is the formula to convert a rad to rev?

I think the first is 1 rev = 2 pi * rad and the second is 1 rad = 2pi / rev

Is that right?

Answer 1

It helps if you use the full terms: radian and revolution. You would discover that there are $2 \pi$ radians in a full circle. It is true that 1 revolution is $2 \pi $ radians. The other direction is $1$ radian is $\frac 1{2 \pi}$ revolution. In the second the revolution should be in the numerator.