PURPOSE: To study motion with constant acceleration by stroboscopic photography of a dropped ball.
DESCRIPTION: A time exposure is made with the polaroid camera while the ball is released and illuminated by the stroboscope/slave. Using about 1200 flashes per minute (20 per second), the result can be analyzed to show that the distances progress geometrically (as the square of the time) for equal time intervals. By appropriate scaling, the acceleration of gravity can be estimated.
REFERENCES: (PIRA 1C30.33)
EQUIPMENT: Golf ball, velvet background on stand, box of styrofoam chips to catch ball, strobe with slave strobe on wooden block, and polaroid camera on tripod, set up as photographed, with opaque projector for class to view photograph.
SETUP TIME: 15 min.
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