Recent content by Baartzy89

Hi all, I'm preparing for a deferred exam this semester after falling ill last year. Just looking over my course notes and have a question. I understand how this works in the big picture scheme. What I don't understand however is how my instructor simplified the original equation. 1. Homework...

Homework Statement a = 2/(0.1v+1) At t = 0; s = 0, v = 0 1) Derive a relationship between t and v 2) Derive a relationship between displacement (s) and v 3) Draw v vs t for 0s ≤ t ≤ 75s & s vs t for 0s ≤ t ≤ 50s graphs Homework Equations a = dv / dt v = ds / dt The Attempt at...

I've managed to work out part C, but the first two are still baffling me - mostly how to create a general solution for variable 'a'. Can anyone talk me through how to do it? The only Linear Homogenous equations I remember solving had constant coefficients. Below is my answer for part C...

If you take the section I originally posted as the intro, and then the questions as follows; A) what is the range of 'a' for which the body moves (i) with oscillations, (ii) without oscillations? B) Find the general solution for any a<4 (Your solution should be a formula depending on the...

Damn, I just realized half of my original question was missing. Doing this on an iPhone is not easy

Yes, m is a constant and is the mass of the pendulum which is 1kg. 'a' is the friction coefficient which is >0. So I take it I need to find a general solution for the equation with variable coefficient 'a' prove that this general solution slows to a rest state as t approaches infinity and then...

Hi all, I'm struggling with this question - I don't really know where to start. So far I have tried putting arbitrary values for 'a' into a quadratic auxiliary equation but using wolfram to calculate the roots gives me complex conjugates that I can't remember a thing about. Question as...

Hi, Just a question on an example in a maths textbook. See attached image for question below. So, I understand that if you set u=sin(x) and v=e^-cos(x) f'(x)=u'.v + u.v' But I'm stuck looking at e^-cos(x), could it also be classified e^(w)? Also, the second step in differentiating...

Hi everybody, this question is on an old exam paper given to us for exam prep purposes. No answers have been supplied however. Am I on the right track? Question: A mass of 0.2kg of saturated refrigerant-134a is contained in a piston-cylinder device at 200kPa. Initially 75% of the mass is in...

After a bit more research I found a worked example for the equation using 3600, and it was to convert back to kg/hr. Here is what I've got together now, if there are mistakes please point them out: Wturbine = ms*(h2-h1) ms = Wturbine/(h2-h1) If state 1 is superheated steam at 10 MPa, 500 deg...

Ok, this is the equivalent of another equation that I found: Wturbine= ms(hgf) But I've also found another equation: ms = 3600*P/he, where P is Load in kW, he specific enthalpy of evap. The 3600 comes from adjustment to the units? And he is the same as hgf. For the first equation that you...

Last question in the paper, stuck on this final section. I haven't been able to find a similar example in the Rankine Cycle section or the mass flow section of the text. Consider a 210 MW steam power plant that operates on a simple ideal rankine cycle. Steam enters the turbine at 10 MPa and...

Ha, I feel like an idiot now. I was hell bent on multiplying them because I thought the result looked better. Typical case of looking for the answer, then to the map. Now when i look at the big picture it all makes sense. Thanks for your help btw, this forum is incredible...

Ok, so I am struggling a bit with the dimensional analysis of the question noqw. I have to admit this area is not one of my strong points. So, 0.6m^3 x 0.001190 m^3/kg = 7.14 x 10^-4 m^6/kg or = sqrt(7.14 x 10^-4) m^3/sqrt(kg) Is there a way of cancelling the m^6 or m^3? Obviously...

Hi everybody, I've got a thermodynamics exam coming in a few weeks. I couldn't sit the exam when I took the subject 12 months ago because of work commitments so I'm sitting a deferred exam this semester. Trouble is I have forgotten most of it, and having difficulty getting help from lecturers...