Weightlessness In Free Fall - Mass In Beaker

Purpose

To demonstrate weightlessness in free fall.

Equipment

Teflon beaker with 50 gram mass attached to the bottom by a rubber band, as photographed.

Images

c4-51

Description

A small mass is attached to the inside center of a beaker using a rubber band. The mass is hung over the edge of the beaker, as in the photograph, and the cup is held in the air and released. Because the mass becomes weightless in free fall, there is no force pulling on the rubber band, so the rubber band pulls the mass into the beaker. An interesting variation of this is to hold the cup upside down, with the mass hanging out of the cup, then release it. Ask the students what will happen when the cup is released: (a) The mass will extend the rubber band, like a parachute, (b) The mass◙will be

References

Eric M. Rogers, Demonstration experiments, AJP 24, 479 (1956). W. W. Sleator, The Meaning of W/g, AJP 15, 251-254 (1947). R. J. Stephenson, Weightlessness of a Freely-Falling Body, AJP 26, 404-405 (1958). Allen L. King, Weight and Weightlessness, AJP 30, 387 (1962). H. L. Armstrong and N. K. Sherman, On a Student's Misconception about Gravity and Acceleration, AJP 30, 528 (1962). Haym Kruglak, Demonstrations of Weightlessness, AJP 30, 929-930 (1962). Haym Kruglak, Apparatus - Lecture Demonstration and Laboratory: Physical Effexts of Apparent "Weightlessness," TPT 1, 34-35 (1963). Laurie