- #1
Brownk
- 3
- 0
Homework Statement
Okay so the question is..A stone falls from rest from the top of a cliff. A second stone is thrown downward from the same height 3.99999 seconds later with an initial speed of 78.3998 m/s. They hit the ground at the same time.
How long does it take the first stone to hit the ground? The acceleration of gravity is 9.8m/s^2.
and
How high is the cliff?
Homework Equations
vf= vi + a*t
vf^2 = vi^2 +2*a*d
d = vi + (1/2)*a*(t^2)
where vf= final velocity, vi= initial velocity, a = acceleration, d = distance, t = time
The Attempt at a Solution
Okay so this is my first time posting on this forum and forgive me if I do something wrong but here is what I tried to do.
For the first rock,
vf= ?, vi= 0m/s, t=?, a= 9.8m/s^2, and d=?
And the second,
vf=?, vi=78.3998m/s, t=?, a=9.8m/s^2, and d=?
Am I missing something or am I missing 3 variables for each of the rocks?? I don't really know where to go without another variable for one of the two...Thanks for any help