Question

What should be done first before removing the starter motor from the vehicle?

Answer 1

Before removing the starter motor, disconnect the negative battery terminal to ensure safety. In the given physics problem, calculate current, voltage, and power supplied to the motor both with and without additional resistance due to corrosion.

Step-by-step explanation:

Before removing the starter motor from a vehicle, it is essential to ensure safety by performing the following step: disconnect the negative battery terminal. This safety precaution is vital to prevent any electrical shorts, which can cause injury or damage to the vehicle's electrical system.

In terms of the physics problem provided:

1. To find the current supplied to the motor (I), use Ohm's Law, I = V/R, where V is the total voltage from the battery, and R is the total resistance in the circuit. The total resistance is the sum of the motor's resistance and the internal resistance of the battery. So, I = 12.0 V / (0.0500 Ω + 0.0100 Ω) = 200 A.
2. The voltage applied to the motor is the voltage dropped across the motor's resistance, which is I * resistance of the motor, hence 200 A * 0.0500 Ω = 10 V.
3. The power supplied to the motor is calculated using the formula P = I * V, where I is the current and V is the voltage applied to the motor. Therefore, P = 200 A * 10 V = 2000 W.
4. When accounting for corroded battery connections, an additional resistance of 0.0900 Ω is added to the circuit. The calculations must be repeated with the new total resistance of 0.1500 Ω. The current would then be I = 12.0 V / 0.1500 Ω = 80 A. The voltage applied to the motor would be 80 A * 0.0500 Ω = 4 V, and the power supplied would be 80 A * 4 V = 320 W.