Guest Linnsan Posted May 9, 2012 Report Share Posted May 9, 2012 I'm going through old paper 1 exams and stumbled upon the following question which I'd like some help solving. I'll show you what I have managed to do so far. "A block of metal at a temperature of 90 C is placed in a beaker of water at a temperature of 0 C. The mass of the metal block and the mass of the water are equal. The final temperature of the water and the metal block is 9 C. Which of the following is the best estimate of the ratio: specific heat of water/specific heat of metal?" I thought the following. The heat lost by the metal= the heat gained by the water. So: m * cmetal * (Tmin-Tmax) = m * cwater * (Tmax-Tmin) Cancelling both masses since they're equal and putting in the temperatures gives: cm * (9-90)= cw* (90-9) cm * (-81)= cw* 81 That's where I got stuck. Have I done something wrong? The alternatives are A: 1/10 B: 1/9 C: 9 10 and the correct answer is C: 9. Please help, and thanks in advance Reply Link to post Share on other sites More sharing options...
HiggsHunter Posted May 9, 2012 Report Share Posted May 9, 2012 Yes, you should have Cm * (90-9) = Cw * (9-0)So Cw/Cm = 81/9 = 9 (Answer C) Reply Link to post Share on other sites More sharing options...
Guest Linnsan Posted May 9, 2012 Report Share Posted May 9, 2012 Ahhhh thanks. It was the 0 that got lost into space Reply Link to post Share on other sites More sharing options...
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