SOLUTION: A ball is thrown vertically upward from the ground. Its distance in feet from the ground in t seconds is s(t)=160t-16t^2. After how many seconds will the ball be 336 feet from theā
Question 1155669: A ball is thrown vertically upward from the ground. Its distance in feet from the ground in t seconds is s(t)=160t-16t^2. After how many seconds will the ball be 336 feet from theā ground? Found 2 solutions by Boreal, ikleyn:Answer by Boreal(15235) (Show Source): You can put this solution on YOUR website! s(t)=-16t^2+160t=336
so -16t^2+160t-336=0
or 16t^2-160t+336=0, changing sign and
t^2-10t+21=0 dividing by 16
(t-7)(t-3)=0
at 3 and 7 seconds.
Answer by ikleyn(52898) (Show Source): You can put this solution on YOUR website! .
They want you solve this quadratic equation
160t - 16t^2 = 336.
Write it in the standard form quadratic equation.
Then solve using the quadratic formula or factoring (if it works) - on your choice.