Question 888092
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.