Nose Basher, 1M40.10

Topic and Concept:

• Work and Energy, 1M40. Conservation of Energy

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Location:

• Cabinet: Mechanic (ME)

• Bay: (A7)

• Shelf: #1

Abstract:

A bowling ball pendulum is held against the nose and allowed to swing out and back.

Important Setup Notes:

• In 2103, there is already a wire attached to the ceiling mount. The bottom end is clipped on another D-bracket above the door located stage-left (see photo below).

Setup and Procedure:

1. Suspend wire from the D-bracket in the ceiling.
2. Clip the bowling ball onto the wire.
3. Have a volunteer stand with his or her back to the wall.
4. Tell the volunteer that it is very important not to move at all during this demonstration.
5. Have the volunteer bring the bowling ball up to his or her nose and release from rest.

Cautions, Warnings, or Safety Concerns:

• Make absolutely sure that the bowling ball falls from rest and is not given a push. This could give the ball enough energy to swing back into the person's face!

Discussion:

When the bowling ball is brought to the volunteer's nose, it is given gravitational potential energy. Since it is not yet moving, the total energy of the ball is just the potential energy. Assuming energy losses due to friction and air resistance to be negligible, this energy must be conserved as per the Law of Conservation of Energy. Thus the ball will reach the same height upon its return to the volunteer. Since there is some energy losses, the ball won't be able to reach the same height and so will be a little further from the volunteer's nose than it had started.

Videos:

• Lecture Demonstration's Youtube Channel

References:

• Conservation of Energy - Wikipedia

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