Recent content by LMH

It's a bit late, but I get it now :) Thank you very much for your help with this! I had problems understanding how we could express m as a function of itself, but I realized that since x = H it actually says m = m. Things got busy last week, so I almost forgot this, but I had to come...

I got the right answer! :biggrin: I guess I just haven't been doing enough exercises because I do all these small mistakes that mess everything up, but this sure made me feel better! :smile: But! I don't understand why m is supposed to be the mass of the water when the tank is full, I'm...

Allright, I now tried to put xm/H in for m in: R = \frac{1}{M+m} ( m\ast\frac{x}{2} + M \ast\frac{H}{2} ) and eventually got: (x^2)m/(H^2) + 2xM/H - M = 0 did you get that? I tried to solve that using the quadratic formula, but I can't seem to manipulate my answer into what I'm...

Why do you say that m is the total mass when the tank is full? I don't understand, my original thought was that the m is the mass of the water at any given time. Making it a variable and not a constant? Or does that not make sense? But if what you say is the case: I don't really...

Hmm.. no m is definately a part of the answer, because: x = \frac{M}{m} * H * ( \sqrt{1 + \frac{m}{M}} - 1 ) according to my book :smile: tiny-yim: I get something like: R = (A(x^2) + B)/(Cx + D) = f(x)/g(x) :smile: I have tried to differentiate this using: f'(x) =...

Hmm... I don't know why I had that 2 in my formula for m, but my algebra was way off anyway. m = d x \pi r^2 That's what I'm working with :smile: So, I put that in to: R = \frac{1}{M+m} ( m\ast\frac{x}{2} + M \ast\frac{H}{2} ) I then tried to differentiate that and used...

I get something complicated :-p I tried to put m = dx2πr2 in: R = \frac{1}{M+m} ( m\ast\frac{x}{2} + M \ast\frac{H}{2} ) Then I tried to differentiate that, but it all became rather ugly pretty quick. I got something like: R' = \frac{ xM + dx^2 pi r^2 - M Hx/2 }{( M + dx 2 pi...

m = d * V ? where d is the density of water and V is the volume given by x2pir2 ? (Could not seem to get the pi to work, it appeared as a superscript for some reason) But then I'm thinking: "d and r are not given in the exercise, and I'm not supposed to include them in my answer." or.. ?

No, I'm not at LMH :) Didn't even know what it was, so I had to google it :p Anyway, thanks for replying! I have thought a bit more about this and what you said. The c.o.m of the water must always lie at the center of the water volume i suppose, that is at x/2. Following that logic, the c.o.m...

Hi! :) This is my first post here, hoping this will help me understand a few things. I'm really stuck at this problem and it is annoying me because I think I understand the theory, but just can't seem to be able to do it. So any help, hints and tips to solve this kind of problem is highly...