Astudent is pulling up a 70 kg bucket at 4m/s^2. how much force does the student need to exert to make this happen?

280N

Explanation: force =mass x acceleration

Force = 70kg x 4ms^-² =280N

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.