Physics 311, Quiz #8

Question 1: If an object moves in a circle with constant speed, then

1. the net force on it is zero
2. some force(s) must push it towards the center of the circle
3. some force(s) must push it forward along the circle

    Answer:  b.  We can label that force(s) "centripetal"

Question 2: If the speed of an object in Uniform Circular Motion doubles, the force required to keep in moving in a circle with the same radius

1. does not change
2. doubles
3. quadruples

    Answer:  c.  Centipetal force depends on the square of speed

Question 3: "Gravity can act as a centripetal force". True or False?

    Answer:  True.  If an object moves in a circle oriented vertically,
             gravity pulls it towards the center of the circle
             during the upper portion of its motion.

This page maintained by Michael Richmond. Last modified Jan 29, 2002.

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