Tom twirls a ball of 0.15 kg on a string in a horizontal circle of radius 0.4 m. The ball travels once around the circle in 1.2 s.
a. Find the speed and acceleration of the ball. What kind of acceleration are we dealing with?
b. Calculate the centripetal force on the ball. What is centripetal force?
c. Calculate the gravitational force between Tom and the ball, when the ball is 1.5 m away from Tom. Assume Tom has a mass of 80 kg. Physically what is the difference between a centripetal force and a gravitational force.