Physics Demo Number: 196
Approximate
Run Time: 5 min
Principle of Equivalence
Demo Description
Use a dedicated tube with an internal spring and captive spherical mass to see the results of the ball's weight disappearing under free fall conditions.
Scientific Principles
A uniformly accelerated reference frame is
equivalent to a gravitational field.
Equipment
A dedicated tube with an internal spring and gravity and friction holding a spherical mass captive on the outside of the tube .
Equipment Location
[E-2-3]
Instructions
The
photo shows the top end of the appparatus, with the ball hanging out
over to the outside of the tube and connected by a string to the
internal spring.
If one holds the tube vertical and releases it momentarily, the ball is sucked inside the tube by
the spring tension.The lower photo shows the new version of the apparatus ( constructed of metal ) to keep
breakage down.
