SOLUTION: I need help please. My teacher gave us the answer, but I can not figure out how to work the problem. A ball is projected upward from the ground. It's distance in feet from th

Algebra ->  Test -> SOLUTION: I need help please. My teacher gave us the answer, but I can not figure out how to work the problem. A ball is projected upward from the ground. It's distance in feet from th      Log On


   



Question 888092: I need help please.
My teacher gave us the answer, but I can not figure out how to work the problem.
A ball is projected upward from the ground. It's distance in feet from the ground in t seconds is given by s(t)= - 16t^2+128t. At what times will the ball be 213 ft from the ground? Answer. 2.4 sec, 6 sec.
Thanks

Answer by Alan3354(69443) About Me  (Show Source):
You can put this solution on YOUR website!
A ball is projected upward from the ground. It's [sic] distance in feet from the ground in t seconds is given by s(t)= - 16t^2+128t. At what times will the ball be 213 ft from the ground? Answer. 2.4 sec, 6 sec.
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s(t)= -16t^2 + 128t = 213
Solve for t.