SOLUTION: Here is a word problem that involves the vertical motion formula of h=-16t^2 + vt +s. The problem is if a person on a creek bed throws a rock straight up at a speed of 64 feet per

Algebra ->  Expressions-with-variables -> SOLUTION: Here is a word problem that involves the vertical motion formula of h=-16t^2 + vt +s. The problem is if a person on a creek bed throws a rock straight up at a speed of 64 feet per       Log On


   



Question 37628: Here is a word problem that involves the vertical motion formula of h=-16t^2 + vt +s. The problem is if a person on a creek bed throws a rock straight up at a speed of 64 feet per second. 1) when will the rock reach a maximum height? 2) when will the rock hit the water again?
This is how I have satrted: I used the formula by putting 64 in the v spot and 0 in the s spot because I started at 0. It looks like this
h=-16t^2 + 64t +0. I worked it out and got 2(1+-1) =t so my answer would be
t=0 and t=4 If that is right then would the answer to #1 be half of that which is 2 seconds and the answer to #2 would be 4 seconds when it hits the water again. Am I on the right path or am I totally off?

Answer by Earlsdon(6294) About Me  (Show Source):
You can put this solution on YOUR website!
Congratulations, you've got it right.
The rock hits the water (h=0) at 4 seconds.
The rock reaches its maximum height (64 ft.) in 2 seconds.