Question

A penny is dropped from a building 425.6 meters from the ground. Determine the time it takes the penny to free fall to the street below.
Group of answer choices

1.43 x 108 s

9.32 s

851.2 s

0.93 s

Answer 1

Use h = (1/2) g t^2 with g ≈ 9.8 m/s^2:
t = sqrt(2h/g) = sqrt(2·425.6 / 9.8) = sqrt(851.2 / 9.8) ≈ sqrt(86.857) ≈ 9.32 s.

Answer: 9.32 s.