Question

an object is dropped from rest the top of a building 19.6 m hi. calculate the a) time for the object to reach the ground and b) object's speed just before it strikes the ground

Answer 1

h=1/2 g*t^2
time=sqrt(2*19.6m/(9.8m/s^2)
=2 seconds

vf=g*t=9.8*2 m/s