Posted by Elizabeth on .
A baseball player hits a baseball into the air with an initial vertical velocity of 48 feet per second from a
height of 3 feet.
8. Write an equation that gives the baseballâ€™s height as a function of the time (in seconds) after it is hit.
9. After how many seconds does the baseball reach its maximum height?
10. What is the maximum height?

Algebra 
Reiny,
height = 16t^2 + 48t + 3
using Calculus,
d(height)/dt = velocity = 32t + 48
= 0 at a max of height
32t = 48
t = 48/32 = 1.5
Maximum height is reached after 1.5 seconds
that height is
16(1.5)^2 + 48(1.5) + 3 = 39 ft
If you don't know Calculus, then you have to find the vertex of the above parabola, usually by completing the square.
A shortcut would be to find the x of the vertex by
b/(2a) = 48/(32) = 1.5
then subbing in just like before to the actual maximum