Question 633505
A baseball hit from home plate is described by the equation
 h = -16t^2 + 100t + 5, where the height is h and the time is t.
The bleachers are 20 feet from the ground.
 When will the baseball land in the bleachers?
 Round your answer to the nearest tenth of a second.
:
The equation for this scenario; h = 20, therefore
-16t^2 + 100t + 5 = 20
-16t^2 + 100t + 5 - 20 = 0
-16t^2 + 100t - 15 = 0
Use the quadratic formula
{{{x = (-b +- sqrt( b^2-4*a*c ))/(2*a) }}}
In this equation x=t; a=-16; b=100; c=-15
{{{t = (-100 +- sqrt(100^2-4*-16*-15 ))/(2*-16) }}}
:
{{{t = (-100 +- sqrt(10000-960 ))/(-32) }}}
You should be able to do the math now, only one solution will make sense