SOLUTION: A baseball hit from home plate is described by the equation h = -16t2 + 100t + 5, where the height is h and the time is t. The bleachers are 20 feet from the ground. When will

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Question 633505: A baseball hit from home plate is described by the equation h = -16t2 + 100t + 5, where the height is h and the time is t.
The bleachers are 20 feet from the ground. When will the baseball land in the bleachers? Round your answer to the nearest tenth of a second.
Answer by ankor@dixie-net.com(22740) About Me  (Show Source):
You can put this solution on YOUR website!
A baseball hit from home plate is described by the equation
h = -16t^2 + 100t + 5, where the height is h and the time is t.
The bleachers are 20 feet from the ground.
When will the baseball land in the bleachers?
Round your answer to the nearest tenth of a second.
:
The equation for this scenario; h = 20, therefore
-16t^2 + 100t + 5 = 20
-16t^2 + 100t + 5 - 20 = 0
-16t^2 + 100t - 15 = 0
Use the quadratic formula
x+=+%28-b+%2B-+sqrt%28+b%5E2-4%2Aa%2Ac+%29%29%2F%282%2Aa%29+
In this equation x=t; a=-16; b=100; c=-15
t+=+%28-100+%2B-+sqrt%28100%5E2-4%2A-16%2A-15+%29%29%2F%282%2A-16%29+
:
t+=+%28-100+%2B-+sqrt%2810000-960+%29%29%2F%28-32%29+
You should be able to do the math now, only one solution will make sense