Question

A flower pot falling 45 meters hits the ground with a speed of _________.a. about 60 m/s. b. about 120 m/s. c. more than 120 m/s. d. about 30 m/s.

Answer 1

Answer:

d. about 30 m/s.

Explanation:

we use the equation for final speed in free fall:

$v_{f}^2=v_{0}^2+2gh$

where $v_{f}$ is the final speed, $v_{0}$ the initial speed, in this case $v_{0}=0$, $g$ is the acceleration of gravity $g=9.8m/s^2$ and $h$ is the height: $h=45m$

so replacing all known values:

we use the equation for final speed in free fall:

$v_{f}^2=0^2+2(9.8m/s^2)(45m)$

$v_{f}^2=882m^2/s^2$

$v_{f}=\sqrt{882m^2/s^2} \\v_{f}=29.7m/s$

so the answer is:  d. about 30 m/s.