The acceleration due to gravity near the Earth's surface, g, can be determined from the time t, measured using an electronic counter, for a sphere to fall a known distance h.
A ferromagnetic sphere is magnetically gripped to a release mechanism. When the sphere is released, it passes through a first light gate which triggers the start circuit of the counter. The counter stops when the sphere reaches the second light gate. The effect of air resistance on the sphere can be disregarded for this experiment.
The time taken for the sphere to fall a distance h is given by the equation
using the initial condition u = 0 m s-1 at t = 0s, the equation reduces to
The time of fall t is measured for different heights of release. A graph of h/m against t2/s2 is plotted using these measurements. The gradient of the plot is the numerical value of 
.
