Question

A bowling ball weighing 71.2 N is swinging like a pendulum at the end of a 3.8 m rope. As the ball swings through its lowest point, its speed is measured at 4.2 m/s. What is the magnitude and direction of the acceleration of the ball at this point?

Answer 1

At its lowest point, the ball feels a downward force due to its weight of 71.2 N and an upward force of tension from the rope. Its motion is circular, so that the net radial acceleration is felt upward toward the center of the circle.

With a tangential speed of 4.2 m/s at the lowest point, its radial acceleration has magnitude

a = (4.2 m/s)² / (3.8 m) ≈ 4.6 m/s²