Question 203283: The equation h=-16t^2+47t+3 gives the height h, in feet, of a football as a function of time t, in seconds, after it is kicked. How long does it take for the football to hit the ground?
Answer by ankor@dixie-net.com(22740)   (Show Source):
You can put this solution on YOUR website! The equation h=-16t^2+47t+3 gives the height h, in feet, of a football as a
function of time t, in seconds, after it is kicked.
How long does it take for the football to hit the ground?
:
When it hits the ground h=0, therfore:
:
-16t^2 + 47t + 3 = 0
Multiply by -1, easier to factor
16t^2 - 47t - 3 = 0
factors to
(16t + 1)(t - 3) = 0
Positive solution
t = 3 seconds for the football to hit the ground
:
:
Check solution when t = 3:
h = -16(3^2) + 47(3) + 3
h = -16(9) + 141 + 3
h = -144 + 141 + 3
h = 0
|
|
|
