Question

A ball is dropped from the top of a tall building h=5m about how long does it take for the ball to hit the ground.

Answer 1

d=-5m
a(gravity)=-9.8m/s^2
vi= 0m/s
t=?
use equation d=vi*t+0.5a*t^2
because vi=0, you can cross out vi*t because anything multiplied by 0= 0
rearrange the equation to say t^2=d/0.5a
t^2= -5/-4.9
t^2=1.02
find the square root...
final answer: t=1s