The line through the center of a rotating object. The object turns around this line?

Why do electron microscopes have higher resolving power than light microscopes?

How to tell if two objects are in thermal equilibrium 1.the objects have the same temperature 2.the objects are the same size 3.the objects are touching each other 4.the objects temperatures are changing

Which pair of quantities includes one quantity that increases as the other decreases during simple harmonic motion?