A trebuchet launches a projectile from ground level on a parabolic arc at a velocity of 40 feet per second. The equation h = −16t2 + 40t models the projectile's h height at t seconds. How long will it take for the projectile to hit its target on the ground?

Step-by-step explanation:

If the projectile is hitting something on the ground, it has a height of 0.  Sub in a 0 for the h and factor to solve for t:

Factor out a -16t to get

0 = -16t(t - 2.5) which means that either t = 0 or t = 2.5

I'd say it has to be t = 2.5, don't you?  ; )

yes

step-by-step explanation:

yes