A steel ball falls from rest through a height of 2.10 m. An electronic timer records a time of 0.67 s for the fall.
a. Calculate the average acceleration of the ball as it falls.
b. Suggest reasons why the answer is not exactly 9.81 m s⁻².
c. Suppose the height is measured accurately but the time is measured to an uncertainty of ±0.02 s.

Calculate the percentage uncertainty in the time and the percentage uncertainty in the average acceleration. You can do this by repeating the calculation for g using a time of 0.65 s. You can find out more about uncertainty in Chapter P1.