Final answer:
The acceleration ar(t) of the rod can be determined using the equation F = ma, where F is the net force. Substituting the appropriate values into the equation, ar(t) = (VBL) / (mR).
Step-by-step explanation:
The acceleration ar(t) of the rod can be determined using the equation F = ma, where F is the net force. In this case, the net force is the force due to the magnetic field, given by F = ILB, where I is the current in the rod, L is the length of the rod, and B is the magnetic field strength. Since the rod is being pulled at a constant speed, we can express the current as I = V/R, where V is the voltage across the resistor and R is the resistance. Substituting these equations into the equation for acceleration, we get ar(t) = (VBL) / (mR).