ATAR Notes: Forum
VCE Stuff => VCE Science => VCE Mathematics/Science/Technology => VCE Subjects + Help => VCE Physics => Topic started by: wolfpack2605 on December 20, 2019, 07:59:44 pm
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Hey,
Im doing my holiday homework for physics 1/2 and I came across this question. I know that I would have to use the first law of thermodynamics and the specific heat capacity equation but I’m not exactly sure how to use both of the formulas in conjunction. Can someone please help that would be much appreciated. I have attached the question to this post.. its question 9 btw
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hey what textbook are you using and what exercise is this ?
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Oki doki so we first can find out the total energy that the water has! We know that there is 200g of water, and the initial/final temp was 20 and 25 degrees. We also know the specific heat capacity of the water is 4200 J kg K.
Q = mcΔt
Q = 4200 X 0.2 X (25-20) = 4200 Joules
Next, the metal! We now know that 4200J was transferred to the metal. We also know that the initial temp was 75 degrees and that the final temp of the metal was 25. There is also 100g of the unknown metal. You could change the numbers to kelvin but since it's only a difference you are looking for there is no need.
Q = mcΔt
4200 = c X 0.1 X (75-25)
c = 840 J kg
Based on the information I would guess the metal is aluminium (if the information didn't say it was a metal I would say glass but it does). The copper is sort of there to throw you off.
hey what textbook are you using and what exercise is this ?
It's the Heinemann Physics textbook and I think AOS 1 review? (I remember this question very well haha)