Help for a projectile motion Q. (1 Viewer)

[Fermentation]

The question is

A cannonball is fired at 80ms/-1 at an angle of 45 degrees to the horizontal. Calculate the height at which the ball hits a vertical cliff 150m away.

The answer is 115.5m, im clueless as how to get to this answer.

 

[jono_z1]

If initial velocity is 80m/s:
u(h)=80cos45
u(v)=80sin45

range = u(h) x t(v)
150 = 80cos45 x t(v)
t(v) = 2.65 s

r= ut + 0.5at^2
= 80sin45 x 2.65 + .5 x -9.8 x 2.65^2
= 115.5 m

hope that makes sense

 

[Fermentation]

thanks for the help, the working made sense to me