Mesh analysis and power dissipation

[Andriy B]

Hi I'm taking an intro course to electrical and computer engineering and I'm having trouble figuring out part c of number one. I have attached a copy of my solutions to parts a and b which I believe are right (correct me if I'm wrong please) however when I calculate the power dissipation of each component and add them up I get a large number. Thank you in advance.

 

[zoki85]

" Determine the power dissipation of each component and show that the sum of the power dissipated equals zero "

Somebody was drunk while writting that assignement ? Dissipative components in that mesh are resistors. Sum of powers dissipated in them must be equal to sum of powers delivered by voltage sources.

 

[Andriy B]

So what's the correct way to solve part c?

 

[zoki85]

After you find current of each branch, calculate power dissipated by every resistor (P_R=I_R²R).Sum these powers up to find total power dissipated in network. Power contribution of voltage source calculate as P_S=V_s⋅I, where I is current through the source (pay attention to voltage source orientation and current flowing through it, depending on network parameters it may be negative). Then show that ∑P_R= ∑P_S holds