Question

A trebuchet launches a projectile from a hilltop 30 feet above ground level on a parabolic arc at a velocity of 40 feet per second. The equation h = −16t2 + 40t + 30 models the projectile's h height at t seconds. How long will it take for the projectile to hit its target on the ground? (to the nearest tenth of a second)

A) 2.8
B) 3.1
C) 3.5
D) 3.9

Answer 1

plug in zero for h , and solve the quadratic for t

quadratic formula works

Answer 2

lik

Answer 3

3.1 seconds