# Circular Motion sheet 1 horizontal KEY ```Circular Motion 一 Practice Sheet 1
Name___________________
Centripetal Acceleration
1. A runner moving at a speed of 8.8 m/s rounds a bend with a radius of 25 m. What is the centripetal
acceleration of the runner?
2. Racing on a flat track, a car takes 5.5 s to round a curve with a radius of 56 m. What is the centripetal
acceleration of the car?
3. A physics student swings a small rubber ball attached to a string over her head in a horizontal, circular
path. The piece of string is 2.0 meters long and the ball makes 5 revolutions per second. What is the
centripetal acceleration?
Centripetal Force
1. A 0.013 kg rubber stopper is attached to a 0.93 m string. The stopper is swung in a horizontal circle,
making one revolution in 1.18 s.
a) Find the tension force exerted by the string on the stopper?
b) If the mass is doubled, but all other quantities remain the same, what would be the effect on the
acceleration and force?
c) If the radius is doubled, but all other quantities remain the same, what would be the effect on the
acceleration, and force?
d) If the period of revolution is half as large, but all other quantities remain the same, what would
be the effect on the velocity, acceleration, and force?
2. A 200 kg car moving at 10 m/s rounds a bend of radius 25m.
a) What is the cars centripetal acceleration?
b) What agent exerts a force on the car?
c) Calculate a numeric value for this force?
3. A 2 kg ball moves at 2 m/s in a horizontal, circular path with a radius of 0.5 m.
a) What is the centripetal acceleration of the ball?
b) What is the tension in the string?
The Conical Pendulum
4. A billiard ball (mass m = 0.150 kg) is attached to a light string that is 0.50 m long and swung so that
it travels in a horizontal, circular path of radius 0.40 m, as shown.
a) On the diagram, draw a free-body diagram of the forces acting on the ball.
b) Calculate the force of tension in the string as the ball swings in a horizontal circle.
c) Determine the magnitude of the centripetal acceleration of the ball as it travels in the horizontal
circle.
d) Calculate the period T (time for one revolution) of the ball’s motion
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