A liquid stream is heated from 25 to 80 C. The inlet and outlet pipes have the same diameter, and there is no change in elevation. Identify (0, -ve, or +ve) U, Q and W and the other terms.
So U = 0 due to steady state W = 0 Q = +ve PE = 0 since no change in elevation
For KE I said it would be +ve because the heat would increase the speed of molecules right? But it says it is 0 as well. Why?
The first law of thermal dynamics doesn't detail with PE. The first law only states energy can not be destroyed or created. At least that it was I believe you are asking.