Circuit Analysis with Two Batteries and an Ammeter

[henry3369]

Homework Statement

http://imgur.com/6Cds4YF

What will the ammeter read when the switch is closed?

Homework Equations

V = IR

The Attempt at a Solution

I already calculated the emf of the battery one the left to be about 27 V.
It seems that the answer to the question is as simple as using V = IR where V is from the battery.
So I = V/R = 25/50 = 0.5 A.

I don't understand why the other battery to the left and the other resistors don't affect the current through the ammeter though. Wouldn't using the numbers for calculating the current, assume that the only item in the circuit is a 25 V battery and one 50 ohm resistor?

 

[phinds]

What is the voltage across the 50 ohm resistor? What factors affect what that voltage is?

 

[rude man]

Use principle of superposition, one battery at a time.

 

[CWatters]

If the battery has no internal resistance it behaves like an ideal voltage source. Think about the properties of an ideal voltage source.