Conversion of PE to KE - Pendulum

To demonstrate that potential energy is converted to kinetic energy during the downward swing of a pendulum.

Equipment Required

• One U-Light Gate

• Two 50 g masses and hanger (a total of 150 g for the pendulum bob)

• Two retort stands

• String

• Ruler

Procedure

1. Set up the masses and hanger to form a pendulum as shown in the diagram. The second retort stand is used to clamp the light gate so that its beam is cut by the pendulum at the bottom of its swing.

2. Pull the bob to one side so that its change in height is 0.025m.

3. Click Start Experiment, wait a few seconds, then release the bob.

The speed of the mass for the first two passes will be displayed. You should record only the first velocity in the table.

Why is the speed of the second pass is less than the first?

4. Repeat steps 2 and 3 three times so that an average velocity can be calculated. Save the results each time if you wish to recall them later.

5. By changing the height that the bob is raised, and repeating steps 2 to 4, complete the tables.