Can you please help me understand how my professor solved this

Problem 6: Consider the diagram below in which a solid conducting rod Ly= 1400-m slides along two conducting posts mounted to the roof. A battery V, = 1.00 EV is connected to each of the posts as shown. The whole assembly is in a uniform magnetic field #= 1.00-7 The resistor /, =100. 2 and the conductors have a resistance that is very small. Note the roof is made of conducting metal, We want to find out how much mass can be put on the sliding rod so that it is at equilibrium. (a) Compute the current in the circuit formed by the battery, resistor assembly. (b) Compute the magnetic force on the rod using the current from a. (c) Using the sum of forces compute the value of the mass M. R. 2 . No - IR. . T-F - LLB 3 R. LB Ha() - ILB] = of 4. Ve - R.Ma/LB Ma - ILB - O Ma = ILB I = MA VO -10 A (0) 1 - L, - B=10 N