Question

A feather is dropped onto the surface of the moon. How far will the feather have fallen if it reaches the surface in 9.00 seconds? Given: g on moon = –1.63 meters/second2
a. 14.0 meters
b. 14.7 meters
c. 16.00 meters
d. 66.0 meters

Answer 1

The feather's vertical position $y$ is determined by

$y=\dfrac12g_{\text{moon}}t^2$

We take the feather's starting position to be the origin, and the downward direction to be positive. Then

$y=\dfrac12\left(1.63\,\dfrac{\mathrm m}{\mathrm s^2}\right)\left(9.00\,\mathrm s\right)^2=66.0\,\mathrm m$

so the answer is D.