SOLUTION: Height of a Baseball The height h in feet of a baseball t seconds after being hit by a batter is given by h(t) = -16t^2+80t+3 a) Determine to the nearest hundredth of a secon

Algebra ->  Test -> SOLUTION: Height of a Baseball The height h in feet of a baseball t seconds after being hit by a batter is given by h(t) = -16t^2+80t+3 a) Determine to the nearest hundredth of a secon      Log On


   

Question 1073425: Height of a Baseball
The height h in feet of a baseball t seconds after being hit by a batter is given by h(t) = -16t^2+80t+3
a) Determine to the nearest hundredth of a second when the ball will hit the ground.
b) During what time interval after the baseball is hit will its height exceed 76 ft.?
Answer by josgarithmetic(39620) About Me  (Show Source):
You can put this solution on YOUR website!
(a)
5.04 seconds

b)
-16t%5E2%2B80t%2B3%3E76
-16t%5E2%2B80t-73%3E0
16t%5E2-80t%2B73%3C0
time between the roots...

These roots, %2880%2B-+sqrt%2812%2A12%5E2%29%29%2F32

%2880-12%2Asqrt%2812%29%29%2F32 from %2880%2B12%2Asqrt%2812%29%29%2F32
%2824%2Asqrt%284%2A3%29%29%2F32
48sqrt%283%29%2F32
about 2.5 seconds