Your car's 31.5 W headlight and 2.15 kW starter are ordinarily connected in parallel in a 12.0 V system. What power would one headlight and the starter consume if connected in series to a 12.0 V battery? (Neglect any other resistance in the circuit and any change in resistance in the two devices. Answer to the nearest 0.1 W.)

Answer 1

figure the resistance of each first R=power/12

then in series, add the resistances, and then power=12^2/Rt

This is acually ignoring a lot of characteristics of motors, as in the motor, effective resistance is not a constant, but depends on the voltage applied, and how fast the motor is turning and developing back EMF. But ignore all this for now.

Answer 2

im still not getting it.