1. The problem statement, all variables and given/known data http://session.masteringphysics.com/problemAsset/1042319/4/YF-25-68.jpg" [Broken] Above is a picture of the circuit! The question is: "What is the terminal voltage of the 4.00-V battery?" 2. Relevant equations I=V/R V_ab = E - I*r 3. The attempt at a solution So first, I calculated the current in the loop... the voltage is 8v-4v = 4v and the total resistance is...6+.5+9+.5+8 = 24 ohms so I = V/R =4/24 = 1/6 from this... V_ab = 4v - (1/6)*(.5) = 3.917v however, the program I am using (masteringphysics) responded "Not quite. Check through your calculations; you may have made a rounding error or used the wrong number of significant figures" when I entered this in... I have no idea where I'm going wrong because in a later question, I used the same method and got the right answer...help! Thanks!