Question

If a ball with an original velocity of zero is dropped from a tall structure and take seven second set the ground what velocity does a ball have when it reaches the ground

Answer 1

Uh I beleive this is a physics question?
You can use Vf=Vi+(a)(t)
a= -9.8m/s (gravity)
Vi=0
t=7s
Ans: -68.6m/s

Answer 2

For a free-falling object without initial velocity,

After seven seconds: v = gt = 9.8 * 7 = 68.6m/s