1. The problem statement, all variables and given/known data A 2.60-N metal bar, 1.50 m long and having a resistance of 10.0 ohms, rests horizontally on conducting wires connecting it to the circuit shown in the figure . The bar is in a uniform, horizontal, 1.60-T magnetic field and is not attached to the wires in the circuit. What is the acceleration of the bar just after the switch S is closed? http://session.masteringphysics.com/problemAsset/1266176/3/27.74.jpg 2. Relevant equations V=IR Fbar=ILB Fgravity=mg Rseries=sum of R Rparallel=(1/R)^-1 3. The attempt at a solution I found the resistance of the parallel resistors(the bar and the 10ohm resistor) to be 5ohms Then the Req=5ohms+25ohms=30ohms Use that and the given voltage to find I. I=4A Use I to find Voltage of the bar. V=20V And then we can find I using the voltage(20V) and resistance of bar. I=2A F=Fbar-Fgravity ma=ILB-mg I get a=8.29 m*s^-2 but Mastering Physics says it's wrong. Where have I gone wrong?