Answer: g = 10.0 m/s/s
Explanation:
For a simple pendulum, provided that the angle between the lowest and highest point of his trajectory be small, the oscillation period is given by the following expression:
T = 2π √L/g , where L = pendulum length, g= accelleration of gravity.
We can also define the period, as the time needed to complete a full swing, so from the measured values, we can conclude the following :
T = 140 sec/ 101 cycles = 1.39 sec
Equating both definitions for T, we can solve for g, as follows:
g = 4 π² L / T² = 4π². 0.49 m / (1.39)² = 10.0 m/s/s
