SOLUTION: This question appeared on our homework: If we stand on top of a 160-foot building and throw a ball up into the air with an initial velocity of 18 feet per second, then the height o

Algebra ->  Equations -> SOLUTION: This question appeared on our homework: If we stand on top of a 160-foot building and throw a ball up into the air with an initial velocity of 18 feet per second, then the height o      Log On


   

Question 1003370: This question appeared on our homework: If we stand on top of a 160-foot building and throw a ball up into the air with an initial velocity of 18 feet per second, then the height of the ball above the ground is given by
H=-14t^2+17t+160.
Here, t is time in seconds since the ball was thrown and H=H(t) is the height of the ball above the ground measured in feet. Determine when the ball hits the ground. Include the correct unit of measure in your answer and round to two decimal places.

Answer by richard1234(7193) About Me  (Show Source):
You can put this solution on YOUR website!
The ball is at the ground when H = 0, so you are solving



Solve using the quadratic formula or a calculator. You will obtain two real solutions, but one of them is negative; discard this solution since it doesn't make sense within the context of the problem.