Engineering Circuit analysis - proportionality

[Mohdoo]

Homework Statement

Homework Equations

First problem:

Second problem:

The Attempt at a Solution

I assume it is acceptable to lump this section into the previous one, as I believe they go hand in hand in this case. My apologies if not.

I am definitely a lot more lost in the second problem than I am in the first. I feel like I may have gotten the first one done just fine, but I am pretty stumped on the second problem. I am stuck at the point where I am at :(

In an example, my professor said to just label the source as I_s and then to assume I_o as 1v, then work from there, but that was an example where we were hoping to find voltage. I wasn't sure if I should do the same, but with current this time. Very confused :(

Any help would be greatly appreciated :)

Cheers!

 

[jegues]

How are you adding the 34 ohm resistor with 72 and 8 ohm resistors?

Certainly the 34 ohm resistor is not in series with those two.

 

[gneill]

In the first problem you're supposed to be looking for the power dissipated by the 4 Ohm resistor, but in your very first step (Thevenin transformation) you've eliminated the 4 Ohm resistor as a separate component. The 4 Ohms that you found the power for in your final step was not the original 4 Ohm resistor, but in fact the sum of the 3 and 1 Ohm resistors!