SOLUTION: If an object is propelled upward from ground level with an initial velocity of 92.5 feet per second, its height h in feet t seconds later is given by the equation h = 92.5t

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Question 269928: If an object is propelled upward from ground level with an initial velocity of 92.5 feet per second, its height h in feet t seconds later is given by the equation h = 92.5t - 16t2. After how many seconds does the object hit the ground? Round your answer to the nearest tenth.
Answer by dabanfield(803) (Show Source):
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If an object is propelled upward from ground level with an initial velocity of 92.5 feet per second, its height h in feet t seconds later is given by the equation h = 92.5t - 16t2. After how many seconds does the object hit the ground? Round your answer to the nearest tenth.

We need to find t when h = 0 so we have:
0 = 92.5*t - 16*t^2
Let's rewrite this as:
16t^2 - 92.5t = 0
t*(16t - 92.5) = 0
The two solutions for this quadratic are when t = 0 and when 16t - 92.5 = 0.
t=0 is when the object is thrown so we want the value of t where
16t - 92.5 = 0
16t = 92.5
t = 92.5/16
Calculate t to the nearest tenth.

SOLUTION: If an object is propelled upward from ground level with an initial velocity of 92.5 feet per second, its height h in feet t seconds later is given by the equation h = 92.5t - 16t2.