Final answer:
To determine the acceleration due to gravity (g) using a simple pendulum, the period (T) for one complete oscillation is needed, along with the length of the pendulum (l). The formula g = 4ππl/T² is used to calculate g after measuring T for the appropriate number of oscillations and converting it to seconds.
Step-by-step explanation:
The student is attempting to determine the acceleration due to gravity (g) using a simple pendulum experiment. To calculate g, one needs to measure the period of the pendulum accurately, which is the time it takes for one complete oscillation. The formula for the period T of a simple pendulum is T = 2πsqrt(l/g), where l is the length of the pendulum and g is the acceleration due to gravity. By rearranging this formula, we can solve for g: g = 4ππl/T². In the student's case, the length of the pendulum is 0.1 m, and the time for 25 oscillations is 2 minutes 20 seconds, which needs to be converted into seconds before being used in the calculation to find T for one oscillation.
However, the student has provided the time for a different number of oscillations than instructed, and there may be a typographical error regarding '25%'. Assuming the student meant 25 oscillations, the time in seconds would be 140 seconds, resulting in T being 5.6 seconds for one oscillation. With these values, one can then calculate g and evaluate the absolute error by comparing it to the standard value of g (9.81 m/s²).