Awave with a period of 1/3 second has a frequency of

if they have a finite resultant

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.

it doesn't. it was imagined up in the middle ages.