math/algebra
posted by Anon .
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.

height = 16t^2 + 47t + 3
when t=2
height = 64 + 94 + 3 = 33 feet high
to hit the ground, height = 0
16t^2 + 47t+3=0
16t^2  47t  3 = 0
(t3)(16t + 1) = 0
t = 3 or t = a negative, which is not valid
it will hit the ground after 3 seconds