SOLUTION: A kicker punts a football from 3 feet above the ground with an initial velocity of 47 feet per second. Write an equation that gives the height (in feet) of the football as a fu

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Question 736931: A kicker punts a football from 3 feet above the ground with an initial velocity of 47 feet per second.

Write an equation that gives the height (in feet) of the football as a function of the time (in seconds) since it was punted.

Find the height (in feet) of the football 2 seconds after the punt.
Calculate how many seconds after the punt the ball would hit the ground.

Answer by ankor@dixie-net.com(22740) About Me  (Show Source):
You can put this solution on YOUR website!
A kicker punts a football from 3 feet above the ground with an initial velocity of 47 feet per second.
Write an equation that gives the height (in feet) of the football as a function of the time (in seconds) since it was punted.
h = -16t^2 + 47t + 3
:
Find the height (in feet) of the football 2 seconds after the punt.
t=2
h = -16(2^2) + 47(2) + 3
h = -64 + 94 + 3
h = 33 ft after 2 seconds
:
Calculate how many seconds after the punt the ball would hit the ground.
h = 0
-16t^2 + 47t + 3 = 0
mult by -1, easier to factor
16t^2 - 47t - 3 = 0
Factors to
(16t+1)(t-3) = 0
the positive solution
t = 3 seconds to hit the ground
:
Graphically, (green line at 33 ft)
+graph%28+300%2C+200%2C+-2%2C+5%2C+-10%2C+50%2C+-16x%5E2%2B47x%2B3%2C+33%29+