- #1
tcheers
- 2
- 0
Hi,
This is a hard question to ask, because it's so vague . . . I have real trouble getting my head around using differentials to derive equations. Stuff like the fundamental differential equation of hydrostatics, eulers conservation of momentum equation in fluid mechanics, and bernoulli's equation. All those ones where they say things like 'consider a rectangular element with horizontal sides of unit length and an infinitesimal height dh'. What's the purpose of using dh? why can't we just use h? what's the difference between dx and ∆x?
I'd just like someone to give an uncomplicated answer as to how you use things dh, dx, dV, for example to derive an equation. What are the rules?
I'm very familiar with calculus and know all about finding the slope of an equation with limits etc, this stuff just seems to get me and perhaps someone could give me a new perspective. Is there a book specifically on this stuff?
Thanks :)
This is a hard question to ask, because it's so vague . . . I have real trouble getting my head around using differentials to derive equations. Stuff like the fundamental differential equation of hydrostatics, eulers conservation of momentum equation in fluid mechanics, and bernoulli's equation. All those ones where they say things like 'consider a rectangular element with horizontal sides of unit length and an infinitesimal height dh'. What's the purpose of using dh? why can't we just use h? what's the difference between dx and ∆x?
I'd just like someone to give an uncomplicated answer as to how you use things dh, dx, dV, for example to derive an equation. What are the rules?
I'm very familiar with calculus and know all about finding the slope of an equation with limits etc, this stuff just seems to get me and perhaps someone could give me a new perspective. Is there a book specifically on this stuff?
Thanks :)
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