Learning Introductory Physics with Activities

Suppose a pendulum is pulled to one side and released at $t_1\text{.}$ At $t_2\text{,}$ the pendulum has swung halfway back to a vertical position. At $t_3\text{,}$ the pendulum has swung all the way back to a vertical position. Rank the three instants in time by the magnitude of the centripetal acceleration, from greatest to least.

Shown below is a motion diagram of a ball rolling along a semicircular track. The time intervals between each pair of consecutive points are equal. The ball starts from rest at point 1, and just reaches point 9 before rolling back down the right side of the track.

Complete this motion diagram by sketching qualitatively accurate vectors representing both (a) the instantaneous velocity and (b) the instantaneous acceleration of the ball at each instant.

Your explanation should describe how you used the diagram to determine each vector and detail why the magnitudes of the vectors are the same or different.