Recent content by marsten

  1. marsten

    Calculating Flue Gas Enthalphy kJ/kg - Marcus

    They apply at 25 °C and 1 atm. I'll ask him if it's necessary to take into consideration. The calculation of the flue gas enthalpy is just a small part of a bigger project I'm working on. Thank you so much for your help Chet! Marcus
  2. marsten

    Calculating Flue Gas Enthalphy kJ/kg - Marcus

    I don't know. But maybe you're right. I found a table and the enthalpy of formation is : ##h_{f_{CO_{2}}}=-394\frac{kJ}{kmol}## ##h_{f_{H_{2}O}}=-242\frac{kJ}{kmol}## Should I just subtract this number from the enthalpy that I originally used, like this : ##h_{fg}=\frac{8\%\cdot...
  3. marsten

    Calculating Flue Gas Enthalphy kJ/kg - Marcus

    It's normal cubic meter.Ok, so I have the volume of each component of the flue gas : ##V_{CO_{2}}=0,59\frac{m_{n}^{3}}{m_{n}^{3}fuel}## ##V_{H_{2}O}=0,55\frac{m_{n}^{3}}{m_{n}^{3}fuel}## ##V_{N_{2}}=5,09\frac{m_{n}^{3}}{m_{n}^{3}fuel}## ##V_{O_{2}}=0,81\frac{m_{n}^{3}}{m_{n}^{3}fuel}## And thus...
  4. marsten

    Calculating Flue Gas Enthalphy kJ/kg - Marcus

    Thank you for your answer. I will try to make things clearer with units. The h represents the enthalphy. I think you are more familiar with using i. The unit in this case is ##\frac{kJ}{m_{n}^{3}}## The V represents the volume of each flue gas component. The unit is...
  5. marsten

    Calculating Flue Gas Enthalphy kJ/kg - Marcus

    Hi 1. Homework Statement I'm trying to calculate the enthalphy of flue gas leaving a gas turbine, in kJ/kg. I just want to confirm that I'm using a correct method. Homework Equations hfg = (VCO2⋅ hCO2 + VH2O⋅ hH2O + VN2⋅ hN2 + VO2⋅ hO2) / (VCO2 + VH2O + VN2 + VO2) ρfg = (p⋅ M) / (R⋅ Tfg)...
  6. marsten

    Icy slope, toboggan, find coefficient of friction

    Nope, not the correct answer. Missed one thing. It's \mu_k=0,43 Thanks again!
  7. marsten

    Icy slope, toboggan, find coefficient of friction

    The final answer will be \mu_k=0,14 Thank you very much!
  8. marsten

    Icy slope, toboggan, find coefficient of friction

    Ok, so it will be something like this? s=\frac{a_{x2}t_2^2}{2}=\frac{g(sin\alpha)\tau^2}{2\cdot2^2}=\frac{g(sin\alpha)\tau^2}{8} ⇒ \tau=\sqrt{\frac{8s}{g(sin\alpha)}}
  9. marsten

    Icy slope, toboggan, find coefficient of friction

    The different accelerations that I have come up with so far is: Acceleration with friction: a_{x1}=g(sin\alpha-\mu_kcos\alpha) Acceleration without friction: a_{x2}=g(sin\alpha) And the given times: Time with friction: t_1=\tau Time without friction: t_2=\frac{1}{2}\tau And by using the...
  10. marsten

    Icy slope, toboggan, find coefficient of friction

    So as long as I put \mu_k=0 I will always get the same result (4,91 m/s^2). Could this acceleration help me anywhere? Or is it not to any use for me?
  11. marsten

    Icy slope, toboggan, find coefficient of friction

    Sorry. The acceleration that I first calculated must be the acceleration without friction and without toboggan.
  12. marsten

    Icy slope, toboggan, find coefficient of friction

    Ahh, should I use 2m? Using the same equation gives me: 2mgsin\alpha-\mu_k2mgcos\alpha=ma_x ⇔ a_x=2g(sin\alpha-\mu_kcos\alpha) ⇒ a_x=2*9,81*sin(30) ⇒ a_x=9,81 m/s^2
  13. marsten

    Icy slope, toboggan, find coefficient of friction

    Some equation to find the distance? Like: s=v_0t+½a_xt^2=½a_xt^2
  14. marsten

    Icy slope, toboggan, find coefficient of friction

    Homework Statement A girl, with the mass m, slides down an icy slope at the time t1=τ. The slope is inclined at 30° below horizontal. The coefficient of kinetic friction between the girl and icy slope is μk. The girl notices that she can slide down the slope significantly faster if she sits on...
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