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Homework Help: Is this correct converting (I am confuse)

  1. Dec 3, 2006 #1
    1. The problem statement, all variables and given/known data

    The temperature difference between the inside and the outside of an automobile engine is 460 C°.

    a) Express this temperature difference on the Fahrenheit scale.

    b) Express this temperature difference on the Kelvin scale.

    2. Relevant equations

    T_F = 9/5T_c + 32
    T_K = T_c + 273.15

    3. The attempt at a solution
    a) i got 860
    b) i got 733.15

    why is it marking this incorrect what am i doing wrong?
  2. jcsd
  3. Dec 3, 2006 #2
    do you have the right amount of significant figures? maybe it asks for 4 or just 3
  4. Dec 3, 2006 #3
    im pretty sure im using the right significant figure since from C to F it gave 860 exact and to convert C to K its basically adding 273.15 i believe. it say my answer is 10%-100% differ to the correct answer.
  5. Dec 3, 2006 #4
    460 degrees celcius seems a bit high. Are you sure it's not 46.0 degrees celcius?
  6. Dec 3, 2006 #5
    Yea, im pretty sure its 460 degrees celcius since i did a direct copy and paste.
  7. May 21, 2011 #6
    Hey soo the answer would be 450 k and 810 F
    Tf = 9/5*450 C
    =810 F
    Kelvin = Celcius hence 450C =450K temp differences are the same change is constant
  8. May 21, 2011 #7
    Since you're expressing a difference in temperature, madhiab would be right in saying that only the the factor difference should be important. So the change in temperature in Kalvin would be exactly the same as the temperature difference in degrees Celsius. However, use the same factor you used above without changing the initial value (notice it only asks for a change) to convert to fahrenheit.
  9. May 22, 2011 #8
    the question is DIFFERENCE in temp. therefore the +273.15 is not needed, as that would be the Teperature of an object at 460C. farenheit i have no idea as i use metric. also since kelvin interval = celcius interval therefore no need to convert (for diff in temperature).
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