SOLUTION: Elias hits a baseball into the air. The equation h=16tsquared+60t+3 models the height h in feet of the ball after t seconds. How long is the ball in the air after it is hit?

Algebra ->  Customizable Word Problem Solvers  -> Travel -> SOLUTION: Elias hits a baseball into the air. The equation h=16tsquared+60t+3 models the height h in feet of the ball after t seconds. How long is the ball in the air after it is hit?      Log On

Ad: Over 600 Algebra Word Problems at edhelper.com


   



Question 872174: Elias hits a baseball into the air. The equation h=16tsquared+60t+3 models the height h in feet of the ball after t seconds. How long is the ball in the air after it is hit?
Found 2 solutions by Alan3354, richwmiller:
Answer by Alan3354(69443) About Me  (Show Source):
You can put this solution on YOUR website!
h=16tsquared+60t+3
--------------
h increases with t.
It will never come down.

Answer by richwmiller(17219) About Me  (Show Source):
You can put this solution on YOUR website!
I suspect that you mean
h=-16t^2+60t+3
Set the equation equal to zero for zero height
0=-16t^2+60t+3
Discard the negative result
t = about 3.7994 seconds
Solved by pluggable solver: SOLVE quadratic equation with variable
Quadratic equation at%5E2%2Bbt%2Bc=0 (in our case -16t%5E2%2B60t%2B3+=+0) has the following solutons:

t%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=%2860%29%5E2-4%2A-16%2A3=3792.

Discriminant d=3792 is greater than zero. That means that there are two solutions: +x%5B12%5D+=+%28-60%2B-sqrt%28+3792+%29%29%2F2%5Ca.

t%5B1%5D+=+%28-%2860%29%2Bsqrt%28+3792+%29%29%2F2%5C-16+=+-0.0493505397925815
t%5B2%5D+=+%28-%2860%29-sqrt%28+3792+%29%29%2F2%5C-16+=+3.79935053979258

Quadratic expression -16t%5E2%2B60t%2B3 can be factored:
-16t%5E2%2B60t%2B3+=+-16%28t--0.0493505397925815%29%2A%28t-3.79935053979258%29
Again, the answer is: -0.0493505397925815, 3.79935053979258. Here's your graph:
graph%28+500%2C+500%2C+-10%2C+10%2C+-20%2C+20%2C+-16%2Ax%5E2%2B60%2Ax%2B3+%29