Using two wooden blocks to model the movement of Earth's plates he pushes one back forward and one back block backward rubbing their surface together which feature is he modeling ?

answer; i believe that the correct answer is (d) a very small amount of mass

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.