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Message: <blockquote data-quote="Treebranch" data-source="post: 1639016" data-attributes="member: 21049">Lol, have to admit that you're right on that one, Coredump. I dunno what I was thinking.But when you say a stream of water isn't the same as a solid object...ehh, it has a center of mass, and conservation of energy works on it too. BTW, my comment stating it has no place in the real world meant with the 1' stream...it doesn't work <img src="https://cdn.jsdelivr.net/joypixels/assets/8.0/png/unicode/64/1f609.png" class="smilie smilie--emoji" loading="lazy" width="64" height="64" alt=";)" title="Wink    ;)"  data-smilie="2"data-shortname=";)" />And yeah...afternoon of drinking combined with not having physics in well...years...yeah. Dunno why I didn't just *think* about that initial equation, hehe.I'll look into it, but really, you should use it shooting straight up as your base case, otherwise you're skewing it. (since the 20' is omnidirectional) And yeah, after giving it about 3 seconds of sober thought, you're right, it won't go 20' if aimed horizontally. But still, thanks for the wake-up, hehe.Quick aside...with an initial velocity of 18 ft/sec...it goes up 5 feet. Maybe you used 9.8 for gravity rather than 32.2?However I should mention that there's nothing wrong with my acceleration assumption, and notice that I did state "as it leaves the decanter." I did not say this acceleration was constant. Think of it as a potato gun. (Then think of that gun shooting LOTS of potatos like a machine gun...then you see why it's fair to treat a "stream" as a solid in regards to momentum, etc. Because really, on a very tiny level, water is solid. <img src="https://cdn.jsdelivr.net/joypixels/assets/8.0/png/unicode/64/1f609.png" class="smilie smilie--emoji" loading="lazy" width="64" height="64" alt=";)" title="Wink    ;)"  data-smilie="2"data-shortname=";)" />And "1 second" of water is hardly arbitrary - it puts everything on a "1 second" scale. Don't say you can't do that either - you obviously DO know what you're talking about, so you know that if you shot a 5 gallon "chunk" of water every second for 6 seconds, you'd shoot just as much water and deliver the same amount of force as a constant stream - think about rocket fuel calculations. You figure out how much momentum is leaving the rocket, and then how fast the rocket (ie it's momentum) has to go to compensate. Force is just the change in momentum - the same thing applies here. So to figure out the force at a given second, you need the mass at a given second, which is 5 gallons of water.</blockquote>

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