What hemisphere are you in? how do you know?

Are you in the north or south hemisphere.

Explanation:

Determining whether you are in the Northern or Southern Hemisphere is easy—simply ask yourself if the equator is north or south of your position. This tells you your longitudinal hemisphere because the Northern Hemisphere and Southern Hemisphere are divided by the equator.

the motion of a pendulum is a classic example of mechanical energy conservation. a pendulum consists of a mass (known as a bob ) attached by a string to a pivot point. as the pendulum moves it sweeps out a circular arc, moving back and forth in a periodic fashion.