SOLUTION: The path of a ball projected in the air can be represented by the equation h=16t^2+64t where h represents height, and t represents time at what time is the ball 48 feet high?

Algebra ->  Customizable Word Problem Solvers  -> Travel -> SOLUTION: The path of a ball projected in the air can be represented by the equation h=16t^2+64t where h represents height, and t represents time at what time is the ball 48 feet high?      Log On

Ad: Over 600 Algebra Word Problems at edhelper.com


    

Question 324951: The path of a ball projected in the air can be represented by the equation h=16t^2+64t where h represents height, and t represents time at what time is the ball 48 feet high?
Answer by Alan3354(69443) About Me  (Show Source):
You can put this solution on YOUR website!
The path of a ball projected in the air can be represented by the equation h=16t^2+64t where h represents height, and t represents time at what time is the ball 48 feet high?
-------------------------------
h=16t^2+64t
Set h = 48
16t%5E2+%2B+64t+=+48
t%5E2+%2B+4t+-+3+=+0
Solved by pluggable solver: SOLVE quadratic equation (work shown, graph etc)
Quadratic equation ax%5E2%2Bbx%2Bc=0 (in our case 1x%5E2%2B4x%2B-3+=+0) has the following solutons:

x%5B12%5D+=+%28b%2B-sqrt%28+b%5E2-4ac+%29%29%2F2%5Ca

For these solutions to exist, the discriminant b%5E2-4ac should not be a negative number.

First, we need to compute the discriminant b%5E2-4ac: b%5E2-4ac=%284%29%5E2-4%2A1%2A-3=28.

Discriminant d=28 is greater than zero. That means that there are two solutions: +x%5B12%5D+=+%28-4%2B-sqrt%28+28+%29%29%2F2%5Ca.

x%5B1%5D+=+%28-%284%29%2Bsqrt%28+28+%29%29%2F2%5C1+=+0.645751311064591
x%5B2%5D+=+%28-%284%29-sqrt%28+28+%29%29%2F2%5C1+=+-4.64575131106459

Quadratic expression 1x%5E2%2B4x%2B-3 can be factored:
1x%5E2%2B4x%2B-3+=+%28x-0.645751311064591%29%2A%28x--4.64575131106459%29
Again, the answer is: 0.645751311064591, -4.64575131106459. Here's your graph:
graph%28+500%2C+500%2C+-10%2C+10%2C+-20%2C+20%2C+1%2Ax%5E2%2B4%2Ax%2B-3+%29

------------------
t+=+-2+%2B+sqrt%287%29 no units given
I don't think your equation is right. The ball never comes back down.