SOLUTION: A rock is propelled upward from the top of a building 80 feet tall at an initial velocity of 136 feet per second. The function that describes the height of the rock in terms of ti
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Question 440187: A rock is propelled upward from the top of a building 80 feet tall at an initial velocity of 136 feet per second. The function that describes the height of the rock in terms of time t is f(t) = - 16t2 + 136t + 80. Determine the time at which the rock reaches its maximum height.
A. 8.5 sec
B. 4.25 sec
C. 3.4 sec
D. 6.8 sec
You can put this solution on YOUR website! 16t2=136t
2t2=17t
t=17/2
The rock will return to its' starting point in 8.5 seconds, therefore, it will reach its apogee (highest point) in half that time, or 4.25 seconds.
16t2=68t
t2=4.25t
t=4.25..
