Energy Conservation (cont.)
Energy: E=U(internal thermal energy)+Emech (mechanical energy)
=U+KE(kinetic energy)+PE(potential energy)
Work: W=Wext(external work)+Wflow(flow work)
Heat: Q heat transfer via conduction, convection & radiation
dE=dQ-dW, dQɬ net heat transfer in dEɬ energy increase and vice versa
dWɬ, does positive work at the expense of decreasing energy, dEɘ
U=mu, u(internal energy per unit mass), KE=(1/2)mV2, PE=mgz
Their difference is due to external heat transfer and work done on flow