A punter kicks a football upward with an initial speed of 48 feet per second. After how many seconds does the ball hit the ground? Use the formula h = rt - 16t2 where h represents height in feet and r represents the initial speed.

Numerical Answers Expected!

Question

A punter kicks a football upward with an initial speed of 48 feet per second. After how many seconds does the ball hit the ground? Use the formula h = rt - 16t2 where h represents height in feet and r represents the initial speed.

Numerical Answers Expected!

hellokitty17 · Answer

@MeganChase @jcoury @OregonDuck

oregonduck · Answer

h = 0 when it hits the ground, therefore: 
-16t^2 + 48t = 0 

--------------------------------------... 
Factor out -16t 
-16t(t + 3) = 0 
: 
Two solutions 
t = 0, when it begins it's upward journey 
and 
t = 3 sec, when it returns to earth

welshfella · Answer

when the ball hits the ground h = 0
so we have 
0 = 48t - 16t^2

solve for t

one of the solutions will be 0 corresponding to start of the kick The other one will be you answer.

oregonduck · Answer

so 3 is the answer