A projectile is shot from the edge of a cliff 160 m above ground with an initial speed of 55.0 m/s at an angle of 40° below the horizontal. How much time does it take the projectile to hit the ground?

Time of flight = 3.61secs

Explanation:

To find time the projectile hits the ground we must find maximum height

H = U^2sin^2theta/2g

H = 55^2*sin^240°/2*9.8

H = 3025*0.4132/19.6 = 63.77

T = sqrt (2H/g) =

T = sqrt 55*2/9.8

T = sqrt13.05

T = 3.61secs