How can I determine whether a power source is providing direct current or alternating current?

I have an anemometer without a data sheet. At first, I thought it was a three-cup anemometer with a reed switch, but after two hours of measuring nothing but house numbers, I opened it. Inside there is a smooth-running motor that is probably intended to serve as a generator. Unfortunately, it is not stated whether…

At school, we have to build an anemometer using SketchUp on a 3D printer. Can anyone help us?

Our problem is that we need to build an anemometer (using the SketchUp program). The anemometer is supposed to consist of a cylinder (the cylinder is to be cast from a single piece). Our problem is that we need to integrate a support for a ball bearing into this cylinder. This just doesn't work from…