Coin on Rotating LP: Application Experiment

Aim

To measure the coefficient of friction by observing where a coin placed on a rotating LP slips, and test this measurement against another method.

Prior Knowledge

• Circular motion.
• Newton's Laws
• Concepts about friction

Description of the Experiment

A dime is placed at various distances from the centre of the disk until it slips. Use the data in the video to figure out the maximum coefficient of static friction between the disk and the coin. The disk is then slowly raised so that it forms a larger and larger angle with the horizontal until the coin slips. Use this method to test whether your measurement of the maximum coefficient of static friction in the first method was good or not. Think of assumptions you made in calculating the value of the coefficient in both experiments. If the assumptions are not valid, should the value decrease or increase? v

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.