Tom twirls a ball of 0.15kg on a string in a horizonal circle of radius 0.4m. Th
ID: 2148179 • Letter: T
Question
Tom twirls a ball of 0.15kg on a string in a horizonal circle of radius 0.4m. The ball travels once around the circle in 1.2s.a) find the speed and acceleration of the ball. What kind of acceleration are we dealing with?
b) calculate the centriperal force on the ball. What is centripetal force?
c) Calculate he gravitional force between Tom and the ball, when the ball is 1.5m away from Tom. Assume Tom has a mass of 80kg. Physically what is the difference between a centripetal force and a gravitational force.
Explanation / Answer
v = 2r / T
v = 2 * 0.4 / 1.2
v = 2.1 m/s
The ball is moving in a horizontal circle ... so the resultant force acting on the ball is just the centripetal force and the acceleration of the ball is the centripetal acceleration
a = v² / r
a = 2.1² / 0.4
a = 11 m/s²