When I think Im making progress I fall upon another problem I dont understand. I really would like to know why the currents through R1 and R2 are negatige and R3 is positive. Without the ground the numbers add up and I dont really understand what ground is for! Can someone shed some light on the subject please

 

Look at voltage drops across the individual resistors to see the direction of the currents.

 

Not sure what you mean Ive got V1 = 24 V2 = 4 V3 = 4 Where does the direction come from because I thought it flowed like it does in the pic here.

 

It probably does. You have the polarity of the voltage source as a guide for that. Measuring current is a relative process, but it's hard to see how one resistor could have a current backwards to the others.

 

The directions you drew are correct.

A negative sign just means the calculation assumed a different direction. In this case the numbers are not consistent, because like I said your drawing is correct.

How did you get those numbers exactly?

The numbers are valid if you defined the currents in a specific way.

 

Yeah you have to pay attention to how the ammeter is connected in the program.

 

Sum the currents into the top node. Is there a problem? (Think conservation of charge.)

 

Yeah Ghar, I used LT Spice to draw the circuit and those are the values it gave. But on paper all calculations were positive?? Thats why I was wondering why 2 of the values are neg and 1 pos.

 

I think LT Spice lets you pick which direction you choose as positive, there's a little arrow that shows up when you go to click on the element.