CM2.5 Test your ideas Now that you know the direction of the acceleration of the
ID: 1780882 • Letter: C
Question
CM2.5 Test your ideas Now that you know the direction of the acceleration of the pendulum bob at the bottom of the swing,use everything that you learned about circular motion so far to make a prediction of the outcome of the following experiment. 10 A 1.0 kg ball hangs from a 1.0 m long string. The other end of the string is attached to a Newton force measuring scale. The string pulls up on the ball exerting a 9.8-N force and the string and ball in turn pull down on the scale exerting a 9.8- N force - the scale reads 9.8-N. Imagine that you pull the ball to the side and release it so that the ball swings like a pendulum at the end of the string. Predict the scale reading as the ball passes directly under the scale (i.e. it it more, less, or equal to 9.8 N?). a. point b. Perform the experiment; record the outcome and compare it to your prediction. Did the outcome support the pattern?Explanation / Answer
the ball follows a circular motion in the pendulum when it's under the scale, it will have a velocity V and max kinetic energy
centripetal force = Tension in the rope ( force with which the string pulls the ball) - the weight of the ball
Tension in rope = mv^2/ r + mg
therefore, scale reading will be more than 9.8 N