All SAT II Math II Resources
Example Question #5 : Solving Functions
A baseball is thrown straight up with an initial speed of 60 feet per second by a man standing on the roof of a 100-foot high building. The height of the baseball in feet as a function of time in seconds is modeled by the function
To the nearest tenth of a second, how long does it take for the baseball to hit the ground?
When the baseball hits the ground, the height is 0, so we set . and solve for .
This can be done using the quadratic formula:
One possible solution:
We throw this out, since time must be positive.
This solution, we keep. The baseball hits the ground in 5 seconds.