Kevin's car battery is dead, but luckily, he has a multimeter and a good replacement battery. The good replacement battery has an emf of ?₁ = 12.5V and internal resistance r₁ = 0.02?; the weak battery currently in the car has an emf of? = 10.1V and internal resistance r = 0.1?. The starter motor has a total resistance of R_S = 0.15?, and is composed of two components in parallel that can be modeled as resistors, the first one having an equivalent resistance of R_S,1 = 0.6?.

Unfortunately the multimeter died before Kevin could measure the second one R_S,2. Kevin also has two copper jumper cables: each one is 3.0 m long and 0.50 cm in diameter, and can be attached as shown in the figure on the right below. Determine:

(a) the equivalent resistance R_S,2 of the second component forming the starter motor,

(b) the total conductance of the circuit if only the weak battery is connected to the starter motor, as shown in the figure on the left,

(c) the current through the starter motor in that case,

(d) the power dissipated in the circuit in that case,

(e) the resistance RJ of a jumper cable (NB: conductivity of copper is ? = 6.0 10⁷S/m),

(f ) the current through the starter motor if the good battery is also connected, as shown in the figure on the right (Hint: there are 3 unknowns ! Find 3 equations by using the junction law once, and Kirckhoff's loop law twice - on the lower loop A-B-S, and on the big, outer loop).

Good battery C D 1 r = 10.020 Q 8= Weak battery 12.5 V L- ----- 12 Jumper cables RJ A B r = 1 0.10 2 8 = Weak battery 10.1 V ! 12 Starter 13 S R = 0.15 0 A B switch I r = (closed) 1 0.10 2 8 = 10.1 V! Starter Starter 13 motor S RS = 0.15 0 switch (closed) Starter motor