Recent content by yossup

  1. Y

    Analysis: prove that ln(x) is a smooth function (i.e. infinitely differentiable)

    thank you.
  2. Y

    Analysis: prove that ln(x) is a smooth function (i.e. infinitely differentiable)

    ah right. i know it's intuitive that 1/x is infinitely differentiable but what do we use to rigorously prove it? taylor series?
  3. Y

    Analysis: prove that ln(x) is a smooth function (i.e. infinitely differentiable)

    f'(x) is just 1/t, so i just go about proving that 1/t is infinitely differentiable?
  4. Y

    Analysis: prove that ln(x) is a smooth function (i.e. infinitely differentiable)

    i guess i meant - we're supposed to derive that f(x) is smooth from f(x) = \int^{x}_{1} 1/t dt, rather than f(x)=ln(x)
  5. Y

    Analysis: prove that ln(x) is a smooth function (i.e. infinitely differentiable)

    Homework Statement Prove that f(x) is a smooth function (i.e. infinitely differentiable) Homework Equations ln(x) = \int^{x}_{1} 1/t dt f(x) = ln(x) The Attempt at a Solution I was thinking about using taylor series to prove ln(x) is smooth but I'm strictly told to NOT assume f(x) = ln(x)...
  6. Y

    Determine the work done by the gas

    isn't that because it's not at constant volume? P1/T1 = P2/T2 only at constant volume... :(
  7. Y

    Finding Efficiency from a P-V Graph

    The figure is a PV diagram for a reversible heat engine in which 1.0 mol of argon, a nearly ideal monatomic gas, is initially at STP (point a). Points b and c are on an isotherm at T = 423 K. Process ab is at constant volume, process ac at constant pressure. How would I go about finding the...
  8. Y

    Thermal Processes: Determine T3

    the volume at the end of step (2) is the same volume as the volume at T1.
  9. Y

    Solving Heat Loss Rate through R-19 Layer and Brick Wall

    um...huh? all i have is that the thermal conductivity of brick is .84J/ s * m * C what exactly is r-19 anyway? arrgh so confusing~
  10. Y

    Thermal Processes: Determine T3

    bbbbump :(
  11. Y

    Determine the work done by the gas

    if it's isochoric, the work done by the gas should be zero but it says I'm wrong so it isn't isochoric?
  12. Y

    Solving Heat Loss Rate through R-19 Layer and Brick Wall

    I have the R-value for the brick wall but I can't find the r-value for r-19 through that wikipedia link...:(
  13. Y

    Calculating Temperature Rise of Air in Bicycle Pump

    Um...we haven't even gone over isentropic processes yet but is the equation your're talking about this? PdV + VdP = nRdT
  14. Y

    Finding Efficiency from a P-V Graph

    uh...just wondering but how do you find out the efficiency from a P-V graph?
  15. Y

    Thermal Processes: Determine T3

    Homework Statement A 1.20mol sample of an ideal monatomic gas, originally at a pressure of 1.00 atm, undergoes a three-step process: (1) it is expanded adiabatically from T1 = 592k to T2 = 390k ; (2) it is compressed at constant pressure until its temperature reaches T3; (3) it then...