I'm stuck on this problem. "You mix 100 ml 60 degree C water with 100ml 20 degree C water. Find the final temperature" Changing 100 ml to .1kg, I set .1*4186*(60-final temp.) + .1*4186*(final temp-20)=0 but my t's cancel out. I know it would work if I set my first half of equation to (Final temp-60) but writing it this way doesn't make sense to me since the final temp. is somewhere between 20 and 60. Please help!!

Question

I'm stuck on this problem. "You mix 100 ml 60 degree C water with 100ml 20 degree C water. Find the final temperature" Changing  100 ml to .1kg, I set .1*4186*(60-final temp.) + .1*4186*(final temp-20)=0 but my t's cancel out. I know it would work if I set my first half of equation to (Final temp-60) but writing it this way doesn't make sense to me since the final temp. is somewhere between 20 and 60. Please help!!

Waqar · Answer

Your should take final-initial temperature on both sides. On left hand side, u r taking initial minus final whereas on right hand side u r taking final minus initial which is wrong