E&M question: power lost in cables

[tamtam402]

Homework Statement

First of all, sorry for my bad english.

I have this problem and I've been trying to come up with something for 1h without success.

A circuit is "given" 100kW (100 000W)
The total resistance of the cables the electricity goes through is 5 ohms.
The voltage difference (deltaV) measured between the 2 extremities of the circuit is 10^4V.

I am asked to measure the lost power in the cables.

I know the answer, and it is 495Watts.

I have no idea how to do this, anyone care to help me out? Even with the answer, I can't come up with the solution.

Homework Equations

P=deltaV^2/R=VI
V=RI

The Attempt at a Solution

Well I tried everything I could. If I plug the given deltaV and given R in the P=deltaV^2/R equation, it gives me a power if like 20000000, which is even bigger than the power mentionned in the problem. I don't understand.

 

[tamtam402]

I just came up with something, but I don't get the same answer.

100 000/10^4=10A current
10A*5 ohms=50V
50V*10A=500W

How did they get 495W instead of 500W though?

 

[marcusl]

This doesn't make sense as written. Can you copy the problem for us verbatim?

 

[tamtam402]

This doesn't make sense as written. Can you copy the problem for us verbatim?

Unfortunately it's from a french book.

It says a power station gives 100kW of power to an electrical network. The resistance in the cables of said network is 5 ohms. After that, it is stated that the potential difference (deltaV) between both extremities of the network is 10^4 volts. I am asked to find the power lost in the cables.

I came up with this:
P=VI, so I=P/V=100000/10000=10A
V=RI, so V=5*10=50A

Using P=VI again, P=50*10=500W

The answer given by the book is 495W. What have I done wrong?