A force of 20N acted on a ball thereby imparting an impulse of 70N's to the ball. For how long did the force act on the ball?

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.

the answer is f1 and d2 because if you put equal force on those two points the beam would balance trust me on this