Question 1115150
 If a ball is thrown straight up from the top of a building that is 407 feet high, the position in feet above the ground is given by the function 
s(t) = -16t^2 + 75t + 407 where t is the number of
seconds elapsed.
a. How high is the projectile after 3 seconds?
s(3) = -16*3^2+75*3+407 = 488 ft
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b. How long will it take for the ball to reach a height of 450 feet above the ground? 
Solve:: -16t^2+75t+407 = 488
-16t^2+75t - 81 = 0
t = 1.6875 seconds
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Cheers,
Stan H.
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