From: poutnik4nntp@gmail.com   
      
   Dne 28/03/2017 v 20:49 liahwang@gmail.com napsal(a):   
   > On Friday, November 1, 1996 at 12:00:00 AM UTC-8, Dogbert wrote:   
   >> Are negative specific heats possible?   
   >>   
   >> For some reason I thought that specific heats could only be positive.   
   >> Here is a problem I am solving.  I got a number for the specific heat   
   >> but it turned out negative.   
   >>   
   >> A 250 gram sample of metal shot is heated to a temperature of 98 C.   
   >> It is placed in 100 grams of water in a brass calorimeter cup with a   
   >> brass stirrer.  The total mass of the cup and the stirrer is 50 grams.   
   >> the initial teperature of the water, stirrer, and calorimeter is 20 C.   
   >> The final equilibrium temperature of the system is 30 C.  What is the   
   >> specific heat of the metal sample?  (the specific heat of brass is   
   >> 092 cal/g*C.   
   >>   
   >> this is what I got:   
   >> 250g*c*(30-98)=50g(1)(30-20)+50g(.092)(30-20)   
   >> mc(delta t)of metal= mc(delta)t of water+mc(delta t) of cup and   
   >> stirrer   
   >> answer=    -.0321cal/g*C for metal   
   >>   
   >> Thanks for any help you can give,   
   >> Joy   
   >   
   There are 3 errors in the homework exercise.   
   The sign,   
   the mass,   
   the heat capacity.   
      
   --   
   Poutnik ( The Pilgrim, Der Wanderer )   
      
   A wise man guards words he says,   
   as they say about him more,   
   than he says about the subject.   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)