What is the voltage of the car in Ohm's Law Application Problem 1?

AI Thread Summary
To determine the voltage at the car, first calculate the total resistance of the copper trolley wire and the rail return. The wire has a resistance of 0.270 ohms per km over a distance of 5 km, while the rail and ground return has a resistance of 0.06 ohms per km. Using Ohm's Law, the voltage drop across these resistances can be computed based on the current of 100 A. The voltage at the car can then be found by subtracting the total voltage drop from the station voltage of 750 V. Understanding the configuration of the wire and rail (series or parallel) is crucial for accurate calculations.
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1. A car, 5 km distance from a station, take 100 A over a 100 mm hard drawn copper trolley wire having a resistance of 0.270 ohm per km. The rail and ground return has a resistance of 0.06 ohm per km. If the station voltage is 750 V, what is the voltage of the car?



Homework Equations


I think this are the relevant equations..
I assume that they are connected in series..
so Icar=Irail
Vt=V[t]station
i don't know what to do with 0.0270 and 0.06 ohms per km..



The Attempt at a Solution


I tried solving for Vcar by Vcar=I[car]*R[car]
where in Icar=100 A and Rcar is 0.0270 ohm/km(1km/1x10^6mm)(100mm)

Vcar=2.7x10^-4.. which is obviously wrong because V[station]=750V and its impossible that the car only takes 2.7x10^-4 V.. Pls help me thanks.
 
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You are given all the information you need to compute the total resistance of the wire and the rail. Once you have the resistance it is easy to compute the voltage drop of the wire and rail. You can then find the voltage at the car.
 
Are the wire and rail in series or in parallel with the car?? What must I do with the voltage of the station??
 
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