Projectile motion of water hose

[mandy9008]

Homework Statement

A fireman 52.0 m away from a burning building directs a stream of water from a ground-level fire hose at an angle of 34.0° above the horizontal. If the speed of the stream as it leaves the hose is 40.0 m/s, at what height will the stream of water strike the building?

Homework Equations

Voy=Vo sin θ
t= Voy / g
y= Voy t - 1/2 g t²

The Attempt at a Solution

Voy= 40.0 m/s sin 34.0
Voy= 22.37 m/s

t= 22.37 m/s / 9.8 m/s²
t= 2.28s

y= 22.37 m/s (2.28s) - 1/2 (9.8 m/s²)(2.28s)²
y= 25.53 m

 

[dulrich]

Your solution method is pretty much correct except for your calculation of the time. The equation you've used is t = v_{0y}/g, which is not valid. You can use t = x/v_x, however since the horizontal motion has no acceleration. That should do the trick.

 

[mandy9008]

22.7 m thanks!