In the Biblical tale of David and Goliath, the giant is slain when David hits him with a rock that he has spun around overhead in a sling with straps made of elastic material. If the rock is spun 100 revolutions per minute, a. What is the rock’s period? b. What is providing the centripetal force on the rock? Be specific.

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Mary and her younger brother Alex decide to ride the 17 ft diameter carousel at the State Fair. Mary sits on one of the horses in the outer section at a distance of 7 feet from the center. Alex decides to play it safe and chooses to sit in the inner section at a distance of 6 feet from the center. What is Mary's centripetal acceleration ay compared to that of Alex's centripetal acceleration a,? Give your answer as a multiple of aA. aA

2. A 50 kg person is sitting on a bathroom scale while riding on a Ferris Wheel. The Ferris Wheel has a radius of 8 m. The scale reads 600 N when the person is at the bottom of the motion. Find the person's speed. 3. A 0.2 kg ball, attached to a string, is moving in a vertical circle. The ball's speed is 7 m/s and the tension in the string is 8 N when the ball is at the top of its path. Find the radius of the motion.

question 4

In each of the four situations below an object is experiencing (nearly) uniform circular motion. State what force is providing the centripetal force required to keep the object moving in a circle: а. A car driving around a track. b. A ball being swung on the end of a string. С. The moon orbiting the earth. d. A rotating wheel.

A ball having a mass of 5.2 kg is swinging at the end of a cord in a vertical circle of radius 2 m at 5 rev/s. What is the tension in the cord when the ball is a. at the level of the center? b. At the bottom of the vertical circle?

A 6x10-4 kg object is moving uniformly on a horizontal circular path of radius r = 6.3 m. a. Find the period, T, the time for one rotation if its speed is 5x104 m/s. b. Calculate its centripetal force.

NASA uses a plane often called the "vomit comet" to reproduce the weightlessness of space in astronaut training. The plane travels in circular arcs at a speed of v = 285 m/s. What is the radius the pilot must fly to create weightlessness as they go around the top of the circular arc? Give your answer in meters.

Two wires are tied to the 400 g sphere shown in the figure. The sphere revolves in a horizontal circle at a constant speed of 7.70 m/. What is the tension in the upper wire? What is the tension in the lower wire?