Buoyant Force on Finger
Publication information:
Abstract
What it shows
An object does not need to float in order to experience the buoyant force.
In this example we see a cup of water at rest on a pan balance. When the demonstrator pushes a finger down into the liquid, the buoyant force of the liquid pushes up on the finger with a force equal to the weight of the displaced water. The incompressible liquid pushes down on the balance as it pushes up on the finger.
Setting it up
A clear plastic cup of water works well. Food coloring is optional. A camera may be necessary in a large lecture hall. Dip the finger smoothly and slowly.
Full text
What it shows
An object does not need to float in order to experience the buoyant force.
In this example we see a cup of water at rest on a pan balance. When the demonstrator pushes a finger down into the liquid, the buoyant force of the liquid pushes up on the finger with a force equal to the weight of the displaced water. The incompressible liquid pushes down on the balance as it pushes up on the finger.
Setting it up
A clear plastic cup of water works well. Food coloring is optional. A camera may be necessary in a large lecture hall. Dip the finger smoothly and slowly.
