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Course: AP®︎/College Physics 1 > Unit 3

Lesson 5: Centripetal acceleration and centripetal force
Science
AP®︎/College Physics 1
Circular motion and gravitation
Centripetal acceleration and centripetal force
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Centripetal acceleration and centripetal force

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Problem

A pendulum consists of a ball with a mass of 0.5 kg attached to the ceiling by a 3.00 m massless rope. The ball is released from rest at some initial angle from vertical and freely swings back and forth. The free body diagram of the ball when the pendulum makes an angle of 45° from the vertical and has a tension of 21 N in the rope is shown below.
Two arrows point out of a central dot. A vertical arrow, labeled F sub M G, points straight down. A diagonal arrow, labeled T, points up and to the right. A thin vertical line extends down from the arrowhead. Between the arrowhead and this line is the label forty five degrees.
Calculate the speed of the mass when rope at this point. Write your answer to 3 significant figures.
  • Your answer should be
  • an integer, like 6
  • a simplified proper fraction, like 3/5
  • a simplified improper fraction, like 7/4
  • a mixed number, like 1 3/4
  • an exact decimal, like 0.75
  • a multiple of pi, like 12 pi or 2/3 pi
ms