Problema Solution
The function y=-16t^2+486 models the height y in feet of a stone t seconds after it is dropped from the edge of a vertical cliff. How long will it take the stone to hit the ground? Round to the nearest hundredth of a second.
Answer provided by our tutors
when the stone hits the ground y = 0 thus we need such t so that -16t^2 + 486 = 0
by solving the quadratic equation
-16t^2 + 486 = 0
we find
t = 5.51 s
click here to see the step by step solution of the quadratic equation
the stone will hit the ground after 5.51 seconds.