Given 2 Sets of Data, Find 3rd (Velocity, Acceleration?)

[hatesmath]

Homework Statement

Falling 20 yards above the ground takes 6 seconds to reach the ground.

Falling 100 yards above the ground takes 9 seconds to reach the ground.

How long would it take to reach the ground from 70 yards?

Homework Equations

v=d/t ?I'm completely clueless. Any help with this would be greatly appreciated! Thank you.

 

[N-Gin]

It's best to assume that body is accelerating at a with initial speed v_{0} and height h_{0}. Maybe some assumptions aren't true, but we don't know that before we try to solve the problem.

So, what you actually have is two equations of the form

h=h_{0}-v_{0}t-\frac{1}{2}at^{2}.

You are given the initial height and the time after which body falls on the ground (to the height h=0). That's all information you need.