Neco 2025 Physics Question 1

A physics practical is arranged to determine the acceleration due to gravity (g) using a simple pendulum. The apparatus consists of a light string attached to a small dense bob. The length of the string is measured from the point of suspension to the centre of the bob and recorded as 0.50 m (uncertainty ±0.005 m). A digital stopwatch is used to time 20 complete oscillations. The recorded times for three successive trials are: Trial 1 – 28.0 s, Trial 2 – 27.6 s, Trial 3 – 27.9 s. Using the relation \(T = 2\pi\sqrt{\frac{L}{g}}\) where \(T\) is the period of one oscillation, determine the value of g for each trial, the mean value of g and the percentage error with respect to the accepted value 9.80 m s⁻². Also discuss possible sources of error and suggest improvements.