- #1
PhoenixWright
- 20
- 1
Member warned to use the formatting template for homework posts.
I have a problem that means:
The jet of water from a fire hose comes with a vo speed. If the hose nozzle is located at a distance d from the base of a building, demostrate that the nozzle should be tilted at an angle such that [tex] tan \alpha = \frac{v_0^2}{gd} [/tex]
so that the jet strikes the building as high as possible. At the point where it hits, is the jet is going up or going down?
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I have tried this:
If the jet reaches the building as high as possible:
[tex]v_y = 0, [/tex] so [tex]t = \frac{v_0 sin \alpha}{g} [/tex]
When the jet reaches the building, x = d, so:
[tex] x = v_0 cos \alpha t \\
t = \frac {d}{v_0 cos \alpha}
[/tex]
I have, therefore:
[tex]\frac{v_0 sin \alpha}{g} = \frac {d}{v_0 cos \alpha} \\
\frac{v_0^2}{gd} = \frac{1}{cos \alpha sin \alpha}[/tex]
I should have [tex] tan \alpha [/tex] where I have [tex]\frac{1}{cos \alpha sin \alpha}[/tex]
What is it wrong?
Thank you!
The jet of water from a fire hose comes with a vo speed. If the hose nozzle is located at a distance d from the base of a building, demostrate that the nozzle should be tilted at an angle such that [tex] tan \alpha = \frac{v_0^2}{gd} [/tex]
so that the jet strikes the building as high as possible. At the point where it hits, is the jet is going up or going down?
---------------------
I have tried this:
If the jet reaches the building as high as possible:
[tex]v_y = 0, [/tex] so [tex]t = \frac{v_0 sin \alpha}{g} [/tex]
When the jet reaches the building, x = d, so:
[tex] x = v_0 cos \alpha t \\
t = \frac {d}{v_0 cos \alpha}
[/tex]
I have, therefore:
[tex]\frac{v_0 sin \alpha}{g} = \frac {d}{v_0 cos \alpha} \\
\frac{v_0^2}{gd} = \frac{1}{cos \alpha sin \alpha}[/tex]
I should have [tex] tan \alpha [/tex] where I have [tex]\frac{1}{cos \alpha sin \alpha}[/tex]
What is it wrong?
Thank you!