1M40.15 Stopped Pendulum
Conservation of mechanical energy
A pendulum is released and the height of the swing is recorded. A rod is then placed in the way of the pendulum and the process is repeated. The height of the swing with the rod is the same as without the rod.
-  1.5" diameter wooden ball on a string
-  Magnetic mount
-  Rod on a magnetic mount
-  Chalk
-  Metre stick
-  Magnetic blackboard or whiteboard
- The pendulum may be made to loop the rod if the height of release and the height of the rod are chosen appropriately
- Practice this demo in advance to drop the ball smoothly and avoid hitting the blackboard
- Do not use a heavy bob as it may pull free from the mount or the blackboard
- Mount the pendulum on the blackboard.
- Raise the pendulum and mark the initial height on the blackboard.
- Release the pendulum.
- Mark the height of the swing on the blackboard.
- Place the rod below the pendulum mount so that it is in the path of the pendulum.
- Raise the pendulum to the marked initial height and release. The pendulum will swing to the same height as before.
- PIRA 1M40.15
- VideoEnc 03-13
- Sutton M-132;DHP Mr-3; DaR M-414; JSMiller p102
- Don't attempt this at home!
- An eye hook was screwed into the wooden ball and a string was attached
- The rod is a 4" length of aluminum bar
If you have any questions about the demos or notes you would like to add to this page, contact Ricky Chu at ricky_chu AT sfu DOT ca.