Recent content by JennyLee1989

  1. J

    Ideal gas law problem -- Pneumatic piston movement with air temperature changes

    Okay thank you for the apology. I wasn’t aware of the obscurity from the grader’s perspective. I will read the LaTex guide per Delta2’s suggestion.
  2. J

    Ideal gas law problem -- Pneumatic piston movement with air temperature changes

    Thank you! Yes, I don't know what LaTeX is and I appreciate all the help I can get.
  3. J

    Ideal gas law problem -- Pneumatic piston movement with air temperature changes

    I should have been more clear with my work but what you've written has been helpful. I came up with 61cm as my answer which I guess is close enough. I am wondering, where you wrote "pressure due to the lead weight," is that the pressure equation that I had above where I used Pressure = Force/Area?
  4. J

    Ideal gas law problem -- Pneumatic piston movement with air temperature changes

    This was very discouraging. I'm just getting back into school. No need to insult my work please.
  5. J

    Heat related problem -- Mercury solidifying liberates some energy

    I got it! Change in temperature is 2K. So 2K + 234K is 236K and if we use two sig figs, then it is 240K. Is that what you got?
  6. J

    Heat related problem -- Mercury solidifying liberates some energy

    If you plug in the numbers, the answer, 240K, still does not come out. I tried changing the signs after reading your warning and the final temp came out to 232K. Either the equation that I'm using is wrong or the answer key is wrong. I am using 234K as the final temperature. Can you please try...
  7. J

    Ideal gas law problem -- Pneumatic piston movement with air temperature changes

    I have come up with the change in height as 170 cm. My professor does not want to solve for the problem for a reason I do not understand. 170 cm is not part of the answer key. The answer according to the answer key is 65 cm. My attempt is: Initial temperature: p=F/A; (50 *9.8) / (pi * 0.05^2)...
  8. J

    Heat related problem -- Mercury solidifying liberates some energy

    I changed my equation to Q = mc(change in temp) - mL and I still get the wrong answer. Here's the work: 81060 = 7 * 140 (234 - Tinitial) - ( 7* 11300). [You're right, the whole equation is losing heat] The answer for T initial came to be 70.57K which is incorrect. The correct answer is 240K...
  9. J

    Heat related problem -- Mercury solidifying liberates some energy

    The subtraction is because the heat is being removed. Isn’t addition used for when heat is added and subtraction for when heat is removed? Also, we are instructed to use the specific heat that is given. I have a feeling that this is just a bad question.
  10. J

    Heat related problem -- Mercury solidifying liberates some energy

    I have used the heat equation and am not able to get the initial heat. This is what I have so far: 81060 = 7 * 140 * (change in temp) - (7 * 11300) + 7 * 140 ( change in temp) I found the change in temp to be 81.71K. But that does not help me with the initial temperature!
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