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-   -   Physics Question, Please help? (https://www.askmehelpdesk.com/showthread.php?t=573281)

  • Apr 28, 2011, 11:06 AM
    rukai2
    Physics Question, Please help?
    1. 2.6 * 10^5 J of heat were added to 1.1 kg of ice initially at -50 Celsius. Find the amount of ice, if any, that remains.
    2. 1.5 kg of ice at 0 celsius was mixed with unknown mass of steam at 100 celsius and soon thermal equilibrium at 23 Celsius was established. Determine the mass of steam?
    3. An ideal gas in a tank at 100 F is allowed to expand quickly into a larger tank. If the volume increased 8 times and the pressure decreased 7 times, what is the new temperature of the gas?
    4. The efficiency of a Carnot engine is 26%. The engine expels 1200 cal of heat per cycle into a cold reservoir at 60 Celsius. The duration of each cycle is .25 seconds. Determine
    a) The temperature of the hot reservoir,___________
    b )the heat absorbed per cycle, and______
    c) The power output of this heat engine, _____________
  • Apr 28, 2011, 11:15 AM
    smoothy

    Why can't the one post wonders take time to read the rules...

    Read this first: Expectations for the Homework Help board
    Do not simply retype or paste a question from your book or study material

    We won't do your homework questions for you.
    You were given the assignment for you to learn.

    If you come up with your own answer and post it for us to critique that is within reason.

    If you have some SPECIFIC questions that you couldn't find or didn't understand, we may help with that.
    But this is your assignment, so show us you have at least attempted to complete it on your own.

    Thank you.
  • Apr 28, 2011, 11:41 AM
    jcaron2
    As Smoothy said, you need to show that you've put some sort of effort into answering these. If there's a fundamental concept that you're having trouble with, we'll be happy to help, but we're not here to simply do your homework for you.

    For the first two questions, you need to understand the concepts of specific heat, heat of fusion, and heat of vaporization. Are you familiar with them? If not, I can explain. Otherwise, where are you having trouble?

    For the third question, you simply need to use the ideal gas law: PV=nRT. Solve for T. Now replace V with 8V and P with P/7, then just solve for the new value of T. How does this compare with the previous value of T?

    Question 4 uses some of the same concepts as 1 and 2. Where are you stuck?

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