<PRE><B>Question 205111</B>
s(t) =-16t^2+32t+40
a = -16 ; b = 32 ; c = 40
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These next two questions pertain to the same problem, but I am not sure how to get the equations that need to find my answers. 
c) After how many seconds will the rock reach maximum height?
Maximum height occurs at t = -b/2a = -32/(2*-16) = 1 second
 
d) What is the maximum height? 
The height when t = 1 is s(1) = -16+32+40 = 56 ft.
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Cheers,
Stan H.

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