Quick Current and Resistance problem

AI Thread Summary
The discussion focuses on calculating power loss in a high-voltage transmission line with a resistance of 0.305 Ω/km and a current of 1.10 kA over a distance of 179 km. To find the total resistance, the resistance per kilometer is multiplied by the total distance, resulting in a total resistance for the round trip of the current. The power loss due to resistance is then calculated using the formula I^2R. Participants clarify the importance of considering the full loop of the transmission line in the calculations. Accurate calculations are essential for determining the efficiency of the power transmission system.
Omat128
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A problem is "A high-voltage transmission line with a resistance of 0.305 Ω/km carries a current of 1.10 kA. The line is at a potential of 800 kV at the power station and carries the current to a city located 179 km from the power station. What is the power loss due to resistance in the line?".

So the formulas i have are I^2R=power and (Change in V)^2/R. I just do not know how to put these together to save my life. I'd appreciate any help i can get. Thanks.
 
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Can you determine the total resistance of the power line?
 
Yup, i got it. Multiply the .305 times 179km, and then just plug that in the I squared R formula. And then you get the power lost. Thanks so much.
 
Not so fast there, buckaroo. The 0.305 Ohms/km is the resistance of the wire. There are two lengths of wire 179km long that make up the transmission line. The current has to circulate around the full loop, right? So what distance should you use in your calculation to figure out the total power lost by the current flowing in the wire(s)?
 
Thread 'Variable mass system : water sprayed into a moving container'

Thread 'Variable mass system : water sprayed into a moving container'

Starting with the mass considerations #m(t)# is mass of water #M_{c}# mass of container and #M(t)# mass of total system $$M(t) = M_{C} + m(t)$$ $$\Rightarrow \frac{dM(t)}{dt} = \frac{dm(t)}{dt}$$ $$P_i = Mv + u \, dm$$ $$P_f = (M + dm)(v + dv)$$ $$\Delta P = M \, dv + (v - u) \, dm$$ $$F = \frac{dP}{dt} = M \frac{dv}{dt} + (v - u) \frac{dm}{dt}$$ $$F = u \frac{dm}{dt} = \rho A u^2$$ from conservation of momentum , the cannon recoils with the same force which it applies. $$\quad \frac{dm}{dt}...
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