Question

Estimate the speed in mph with which water comes out of a garden hose using your past observations of water coming out of garden hoses and your knowledge of projectile motion. (Take the inclination angle to be 45°, the initial height to be 1.0 m, and the range of the stream to be 4 m.)

Answer 1

Your knowledge of projectile motion tells you that the range R and max height H are

R = (v^2 sin2θ)/g
H = (v sinθ)^2/2g

You know θ,g,R,H so you should be able to come up with v.