|g – GRAMOPHONE TURNTABLE
The aim of this experiment is to determine the acceleration of gravity (g) using a
gramophone turntable as a timing mechanism.
YOU WILL NEED:
A gramophone turntable (one that can run at 45 rpm or even 78 rpm is better) Carbon paper or plasticene Ball bearing (large) Protractor Sheet of white paper
WHAT TO DO:
Place a sheet of white paper on the turntable and put a piece of carbon paper on top of it with the carbon side facing down. Stick a white line (made from a strip of paper) onto the carbon paper along a radius of the turntable.
Start the turntable and drop the ball bearing from a height h when the line passes under your hand onto the carbon paper. The ball bearing will hit the carbon paper when the turntable has rotated through an angle . Repeat the process for a series of value of h between about 1m and 40 cm.
Time n revolutions and hence determine the time for one revolution (T).
The time of fall is then (t) = [/360]T
ANALYSIS AND CONCLUSIONS:
Plot a graph of h against t2 and hence use the graph and the formula:
h = [½]gt2 to calculate g.
g = The gradient of the graph x 2