Search results

  1. 1

    MATLAB Extracting multiple data in a MATLAB matrix

    Hey everyone. I want to extract numerical data from files let's say g0001.txt to g0060.txt and store it in a matrix with each element is an array. like this: M=[g1() g2() g3() ...g60()] matrix order can be 1 x 60 , i.e. to say 1 row and 60 columns and each element is an array...
  2. 1

    Fortran Writing strings/arrays to files in FORTRAN 77

    Hey guys i am a little confused in how to write arrays to a output file in FORTRAN 77. Here is the piece of code: Please assume that rri and eei arrays have been defined correctly above open (16,file='output.out') write (16,6100) rri eei format (5e16.8) However in the output file...
  3. 1

    Fortran Help with fortran code

    Yup, well that was the error. Thank you all of you, this program has been fun to debug. I don't know why the compiler didn't show this error or why the hell it was pointing to courant sub routine. I had to find this one manually by reading it.
  4. 1

    Fortran Help with fortran code

    Just a thought, do you guys see a possible error in this line? open (16,file='boplot00.out',status='old') write (16,6100) rri,eei 6100 format (5e16.8) Is the correct way to open a new file for storing results ?
  5. 1

    Fortran Help with fortran code

    Hey Mark44, that's a great idea. I did, as you said and added the print statement. print*, x0, e(k-1), x0/(e(k-1) Well none of the values were equal to 0 or negative, hence i don't think that was the error in code. But it's a start in debugging, and I would love to hear more such...
  6. 1

    Fortran Help with fortran code

    Do any of you guys have experience with f2c program ? I was wondering whether I could translate the given FORTRAN code to C, which will make debugging and changing code easier.
  7. 1

    Fortran Help with fortran code

    In case if you guys are running the code, here are the sample values: dt:1 r0:10 xmw:1 scal:2 isw:2
  8. 1

    Fortran Help with fortran code

    Mark44 : Even after i correct as per your possible typo, the same error comes. Just curious, what made you think of the typo ?
  9. 1

    Fortran Help with fortran code

    Sorry, but i am unable to see the difference ... where did you exactly change ?
  10. 1

    Fortran Help with fortran code

    Mark44, here it is:(it is huge) program coad1d parameter (n=400) implicit double precision (a-h,o-z) common /const/ rq0,dlnr,scal,ax common /cour/ c(n,n),ima(n,n) common /grid/ g(n),r(n),e(n) common /kern/ ck(n,n),ec(n,n) dimension...
  11. 1

    Fortran Help with fortran code

    Hey everybody, I am a mechanical engineer and new to Fortran(I have decent experience in programming in C, Matlab and understand languages similar to them). However the Fortran programming structure is new to me. Hence I am facing problems debugging a Fortran code. Here is the link of the code...
  12. 1

    Fortran Help with fortran code

    Sorry for again disturbing all of you guys, but there seems to be another problem in the program. It runs initially, but when I enter the values initially asked, the program stops mid-way showing an error: Run-time Error *** Error 112, Reference to undefined variable, array element or...
  13. 1

    Fortran Help with fortran code

    Hey everybody, I am a mechanical engineer and new to Fortran(I have decent experience in programming in C, Matlab and understand languages similar to them). However the Fortran programming structure is new to me. Hence I am facing problems debugging a Fortran code. Here is the link of the code...
  14. 1

    Need help to understand the reason behind the sunset effect seen here

    Someone I know clicked the image attached while on an airplane... I am confused regarding the strange contrasting pattern of clouds seen in this picture which makes us perceive that sun is leaving a trail(not really)... What caught my attention in this picture is the orientation of the...
  15. 1

    (Thermal) Vibrational degrees of freedom

    Look at DOF in another way... Try to find the minimum number of coordinates you need to know the exact position of CO2 molecule , there are three atoms with each having x,y coordinates. Assume that you know the distance between Carbon And oxygen atoms.
  16. 1

    Fluid Mechanics Problem

    I think your solution is wrong... it should come h1=3h2...but it's the last line of the question that's bugging me... i think we got to understand h2 relative to h1...
  17. 1

    Is this a tensile failure?

    Can't you just upload the pic here ? to view the pic one needs to sign up for flickr...
  18. 1

    Schools Good college for MS in Mechanical

    Well i am into designing of low - cost products right now, and am confused what sort of specialization should i undertake which helps me in designing new and innovative products. For ex. i have developed a low cost method for domestic cylinder users a way through which they can get the amount of...
  19. 1

    Schools Good college for MS in Mechanical

    Hi everybody, i am currently studying Mechanical engineering and about to enter second year... i was thinking of doing my masters in mechanical from world renowned colleges like MIT, Caltech, etc. ... i want to know which among such colleges are the best ? And what should one have to do to...
  20. 1

    Doubt in light

    The relationship between refractive index and speed of light is by it's definition.The result sin i/ sin r is obtained by Fermat's principle which says light travels a path in shortest time.
  21. 1

    Best place for physics in India -- Undergraduate

    @nomad19095 : Given JEE and AIEEE??How did these exams and other exams go?
  22. 1

    Best place for physics in India -- Undergraduate

    What does written mean?Have you given the entrances then?
  23. 1

    Best place for physics in India -- Undergraduate

    Thank you very much.I am deeply interested in physics and thought of going to CMI.But after reading that article I don't think that I am going to that institute
  24. 1

    I'm trying to understand why e works this way

    e is a number originally defined as 1+(1/1!)+(1/2!)+(1/3!)+(1/4!)...∞. When you find the derivative of a^x then you get it as a^x*logea.When you find the derivative of a^x using first principle then you find the limith→0 (ah-1)/h.This limit on solving using binomial theorem for a^h you get the...
  25. 1

    Length of Sine Curve

    Thanks for your effort.It means a lot.Can you also suggest where else can I put up my query? Or mail someone? Any help will be useful.
  26. 1

    Length of Sine Curve

    I know elliptic integrals.It comes when you try to find time period of a simple pendulum without taking usual approximation:that angular displacement is very small and that sin(θ)≈θ in radians.But even elliptical integrals can't be solved analytically.You have to solve it in a...
  27. 1

    Best place for physics in India -- Undergraduate

    Are degrees from CMI good?Do they have good value?
  28. 1

    Conservation of Angular Momentum - Man firing a bullet on a metal rod at an angle

    Oh!Sorry.I didn't think about that.Well then all terms written by you are correct.But linear momentum should be conserved in such problems if mass of man is not much greater than mass of bullet.However in your problem it seems that book has assumed the mass of man to be much greater than mass of...
  29. 1

    Conservation of Angular Momentum - Man firing a bullet on a metal rod at an angle

    Yes it's correct.But should we neglect mass of man in comparison to mass of bullet? If not then conserve linear momentum along cos component of velocity, i.e. M*v=-m*vB*cos(θ). '-' sign indicates man gets velocity in opposite direction of motion of bullet.Then the problem bcms complex bcs...
  30. 1

    Periodic function in integral

    You can prove it graphically.By observing overall sum of areas.Areas above x-axis are positive, while below x- axis are negative.So when from nT to 0 all the positive and negative areas get added and cancel each other except from T to 0.That's your RHS.
  31. 1

    Length of Sine Curve

    I tried to find the length of a sine curve using calculus.I got stuck in the integral of integral(sqrt(cos(x)^2+1), x, 0, a). Limits are from 0 to point a,i.e. length of curve from 0 to any point a.With some approximations I found out the length of sine curve as a result.I have attached the...
  32. 1

    Speed of water and height involving fluid mechanics

    Can you tell me that what would you do if nozzle is not very small, i.e. it has a small area 'a' and let's finite amount of water out(not point sized particles)??You also know area of topmost layer of water as 'A'. Think it yourself.The answer becomes more interesting. Hint:In that case don't...
  33. 1

    Speed of water and height involving fluid mechanics

    Just take a small element of water of mass dm at a height s above the nozzle. Initial energy=Potential Energy=dm*g*h Final energy after just coming out from nozzle(assuming it to be at height 0)=0.5*dm*u^2 Equating final and initial energy you can get u=sqrt(2gs). Here however we assume that...
  34. 1

    Pulley on a Spring

    You can find time period from purely energy method. This is how: Initial energy at mean position=potential energy stored at spring=0.5*k*d^2 Where d is extension of spring at mean position(mg/k).This term is constant. Now write energy at any position=potential energy stored + kinetic energy of...
  35. 1

    Force on a connecting rod

    connecting rods touch disc at two points at r, and R.One is anti-clockwise torque and other is also anti-clockwise.So both get added.That's what it seems if you have both rods touching disc to brake it down.It seems unclear here.Though you haven't stated it here that only one rod touches disc or...
  36. 1

    Force on a connecting rod

    Yes it's tangential force.And both torques will get added.
  37. 1

    Speed of water and height involving fluid mechanics

    Use energy conservation to get velocity(u) of water just outside nozzle.You will get u=sqrt(2gs). Assuming nozzle is very small.Here s is distance of nozzle from topmost layer of water(4.00m). After getting velocity use kinematic equation (v^2)=(u^2)-2gh. For highest point v=0.Thus getting...
  38. 1

    Force on a connecting rod

    I think you have done wrong.Here you need to check torques as it is not point object but a rigid body.
  39. 1

    KG to KGF conversion

    Weight=Mass*Acceleration due to gravity=m*g Assuming 60kg weight at 9.8 m/s^2 calculate mass m(60/9.8=6.122)). This will give mass.Now multiply mass by 9.6 to get kgf or weight for that place(6.122*9.6=58.775). Use results in significant figures if needed.
  40. 1

    Moment of Inertia of Door

    But in which plane? I mean that whether the door is on floor and rotating about vertical axis or in an erect position rotating about vertical axis.Moment of inertia in both cases is different.
  41. 1

    Moment of Inertia of Door

    Your question is confusing.Give more details.Whether the door is rotating in vertical plane or horizontal plane??
  42. 1

    Current and voltage in AC

    Compare AC with waves on a string.Particles in string oscillate about their position but net displacement in a time period their net displacement is zero.Yet your energy gets transferred across string and even released if there is some damping(just as resistance in case of DC or AC circuits)...
  43. 1

    Kinematic Problem: Car Chase

    Write kinematic equations for car a and car b separately. For car a:d=0.5*a*(t^2) For car b:s=v*t+starting distance. equate d and s.Get t Here a=4.5(acceleration) v=25(velocity) t is time in seconds.
  44. 1

    Find the power required to pull loop through constant magnetic field

    If you have(Covenant32) calculated correctly then it might be.Method remains as stated.All rest is calculation.
  45. 1

    Finding limit- greatest integer function

    we know that t-1< [t] <= t. Replace here t by 1/x. I think your answer is correct.This form of inequality is more formal method.
  46. 1

    Find the power required to pull loop through constant magnetic field

    Consider the loop consisting of atoms.Each atom has electron's and in metals these electrons are free to move.Due to action of magnetic field we have force on electron as e*(v x B). Here 'x' is cross product of vectors.So electrons move to one end and all protons remain where there are.Thus...
  47. 1

    Help needed to plot a graph

    Those lines are just drawn for sake of our convenience, to show connection between two very close numbers.You are right they don't exist there. You will also get such lines for Fractional Part of x ({x}).
  48. 1

    Help needed to plot a graph

    The attachment shows the graph using Microsoft Maths.Step function is also known as Greatest Integer Function(GIF).In GIF you only take integral part of that number. Ex. No. is 2.348947 Here GIF of this(also represented as [2.348947]=2 known informally as box function-same as GIF) is 2...
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