Recent content by Mary2100

  1. M

    Method to calculate work while moving two walls

    Nothing move ? Look at that image: At start, the position is 1, at final it is 2. The motor 1 take the black wall. The motor 2 take the pink wall. The motor 3 take the green wall. The black arm turns, no ? the green wall moves, no ? for me the motors 1 & 2 recover an energy. The motor 3...
  2. M

    Method to calculate work while moving two walls

    I don't understand. There are 3 motors, each motor don't consume any energy ?
  3. M

    Method to calculate work while moving two walls

    "What is the body of the motor mounted on?" the motor of the z wall is fixed on the ground, the motor for the z wall is a linear motor or use a gear (the z wall moves in translation).
  4. M

    Method to calculate work while moving two walls

    "We've been trying to explain that to you for some time now." Sorry if I need time for that. "If you disagree then please provide a diagram showing how the external device works. How is your "external device" different to the clamp or spring I proposed?" I don't know what you called a diagram...
  5. M

    Method to calculate work while moving two walls

    "or the system explode." An external device controls the walls. The walls x, y and z are independent. That external device needs to give an energy to move in translation the z wall and recover the same energy from x and y. I would like to know if my calculations are correct for the walls x and y...
  6. M

    Method to calculate work while moving two walls

    "Consider a pneumatic lift with incompressible fluid. When I push one piston down, the other one goes up. Now, if I put a car on top of one piston, it takes more work for me to push down on the other piston than without a car. The details of the pneumatic lift are irrelevant to the calculation."...
  7. M

    Method to calculate work while moving two walls

    "Basically, if you have two sides pushing on opposite sides of a massless wall, all the work is external to the wall, and depends on the pushers." I don't understand, the walls don't pushing themselves. The difference of pressure (inside/outside) give a force on the walls. I rotate independently...
  8. M

    Method to calculate work while moving two walls

    "If the area isn't changing (hard to see how that is possible), then there is no work done." I agree, but I want the work from x and y not x +y +z. Yes, the area doesn't change because I rotate clockwise the wall x, I rotate counterclockwise the wall y and I move up the wall z, the external...
  9. M

    Method to calculate work while moving two walls

    " I'm not convinced that the constant volume stipulation is even achievable with that geometry ." The geometry can respect the volume constant with that: The area is constant so a*b=0.5, so a=0.5/b Pythagoras's theorem: c²=a²+b² (a, b, c are not x, y, z) b=c*cos(α): The length of the z wall...
  10. M

    Method to calculate work while moving two walls

    "No change in pressure or volume means no work." I agree, the external device recovers an energy from the walls x and y but it needs to give the same energy to move the wall z. There is a difference of pressure, inside the triangle there is the pressure 2P and outside there is P, so there are...
  11. M

    Method to calculate work while moving two walls

    No, the volume is constant and the pressure too. The external device needs to give an energy to move the z wall. I supposed there is no mass, even the gas, I would like to simplify the calculations. I drawn the triangle at start and at the end (pink):
  12. M

    Method to calculate work while moving two walls

    Hi guys, It is not some homework, so I think it is better to post here. I would like to know if my method is correct for the work of the walls x and y. I suppose no mass, no friction and the gas keeps its temperature constant. An external device modify the shape of a triangle but it keeps...
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