80. Measurements of g

Simple Measurement of g: Heights of 6, 9, and 12 feet are marked up on lecture hall wall. Time intervals are announced by a metronome set to 80 beats/min. (Dt = 0.75 sec.) The demonstrator stands on a ladder and drops a ball from various heights on the beat of the metronome. Nine feet will be found to be the height for which the next beat is simultaneous with the ball hitting the floor. Then, g = 2h (Dt)2. This demonstration requires moderately good reaction time. A student volunteer may help. AVAILABLE ONLY IN KNUDSEN 1200

Measuring g with Sonic Basketball: In this experiment the kinematics of a basketball under the influence of gravity is studied quantitatively. The ball is thrown upward above a motion sensor to plot its position, velocity and acceleration as a function of time. (See Sonic Basketball)