Additional Info

• ID Code: G1-20
• Purpose: Encourage thought about the motion of a pendulum and related forces.
• Description: A simple pendulum bob is released from rest at one end point of its motion. A peg interrupts its motion, and we see that the conservation of the pendulum's energy causes it to attempt to rise to the same height as it started; but the effective period has changed.

  Now the lower peg is removed, and the pendulum bob is raised and released a second time. When it gets to the other extreme, the string is "cut" by releasing it from the upper peg. The question to challenge your students with involves how the pendulum bob will move after it is released: will it move back retracing its path, due to its angular momentum and centripetal force; will it move downward and slightly toward the original path; will it move straight downward; or will it both move downward and continue to move slightly away from its original path?

• Availability: Available
• Loc codes: FS2, tools
• Videos-1: Demo in Action
• Videos-2: Pendulum at Maximum Amplitude
• Videos-3: Introduction video on YouTube