# Science 12

Gravity causes objects falling towards Earth to accelerate at 9.8 m/s2. Two students measured the fall times of a tennis ball and a baseball, using a stopwatch that was accurate to the nearest tenth of a second. The fall times were used to calculate the acceleration of the objects as they fell from a given height

Experiment 1

The students dropped a 100 gram tennis ball and a 250 gram baseball from a window 3 meters from the ground. The recorded fall times are shown in Table 1. For the tennis ball and baseball the average fall times were .7 seconds and .9 seconds, respectively. The average accelerations were calculated to be 8.5 m/sec2 and 8.0 m/sec2, respectively.

Experiment 2

The students repeated the procedure described in Experiment 1, but dropped the balls from a height of 10 m. The results are shown in Table 2. For the tennis ball and baseball the average fall times were 1.3 seconds and 1.6 seconds, respectively. The average accelerations were calculated to be 8.9 m/sec2 and 7.6 m/sec2, respectively.