Ball constrained to a ring: Qualitative Testing Experiment

Aim

To test the necessary conditions for circular motion at constant speed.

Prior Knowledge

• Circular motion at constant speed.
• Newton's Laws.
• Free-body diagrams.

Description of the Experiment

A wooden ball is placed inside a large metal ring placed on a flat surface, and set in motion inside of the ring. Part of the ring can be removed, making a gap and allowing the ball to escape from the ring.

Use your understanding of circular motion to predict what the path of the ball will be after it reaches the gap.

1. Explain your prediction, make sure it is based on what you learned from the previous experiments.
2. What other models do you need to use/assume to predict the path of the ball after it exits the ring?

Youtube movies can be stepped frame by frame using the , and . keys on your keyboard. If you want to download the movie to your computer, right-click or control-click HERE.

Questions

Now that you have watched the video, did your prediction agree with what you observed? If your prediction did not match the outcome of the experiment, decide how you need to change your reasoning that led to the prediction to explain what you see.