Lifting and Dropping a Mass with Changes in Pressure

Concept Overview: 

Atmospheric pressure is considerable.

Lecturer Procedure

Step(s) to Follow

1. Open the stopcock on top of the heavy cylinder.
2. Place the hook on the piston under the handle of the heavy weight.
3. Adjust so that movement of a quarter/half an inch will lift the weight.
4. Attach vacuum hose to fitting on top of cylinder.
5. Start the pump.
6. Turn the stopcock to the off position.
7. Remove the hose.
8. Open the stopcock fully.

Expected Result

Weight will be picked up and held in place within seconds of turning the pump on.  When the cock is re-opened, the weight will fall.

There are no spoken words with this demonstration.