A trebuchet launches a projectile on a parabolic arc from a height of 47 feet at a velocity of 40 ft/s.

Using the function h(t) = -16t^2 + vt + h0, determine when the projectile will first reach a height of 60 feet and how many seconds later it will again be at 60 feet.

Respuesta :

Answer:

First at

5/4 +(√3)/2s

then at

5/4 -(√3)/2

Step-by-step explanation:

h(t) = -16t^2 + 40t + 47 = 60

so all we need to do it find the solution of the equation

so 16t^2 - 40t + 13 = 0

and as we know

root = (-b+-√(b^2-4ac))/2a

so

root = 5/4 +-(√3)/2