DC motor. Calculate the current

[gucci]

Homework Statement

The coil of a DC motor has a resistance of 2.0 ohms. The motor is runned by a battery of 12 V and an internal resistance of 0.5 ohms.
a) Calculate the current at the moment the motor is started
b) Calculate the current when the motor is running at 600 RPM , when there is an induced counter EMF of 10 V in the coil.

Homework Equations

I = E / R

The Attempt at a Solution

a) is already solved I = 24 A

help with b), please

 

[BvU]

If you know the voltage from the internals of the battery and the voltage over the coil, what does the internal resistance of the battery see ?