Does a fan that is not spinning have energy?

A fan always uses mechanical energy, that's why, when you turn it off, it eventually stops spinning, and it would even if it were frictionless, because the built up mechanical energy (rotational kinetic energy) gets used up from continuing to move air.

Yes, when dealing with electricity as long as there is an input source there is always built up energy waiting to be used also known as kinetic energy. The fan is not spinning but if it were turned on it would spin instantaneously.

the small 0.38-kg slider is known to move from position a to position b along the vertical-plane slot. determine (a) the work done on the body by its weight and (b) the work done on the body by the spring. the distance r = 0.70 m, the spring modulus k = 154 n/m, and the unstretched length of the spring is 0.53 m

explanation:

-reverse card

the temperature in kelvin of 2.0 dm3 of an ideal gas is doubled and its pressure is increased by a factor of four. what is the final volume of the gas