How many kilos of copper wire is needed for 4km copper wire with a cross section of 25 square mm? (copper density = 8.9 times 10 cubic kg / M cubic) ↘

How many kilos of copper wire is needed for 4km copper wire with a cross section of 25 square mm? (copper density = 8.9 times 10 cubic kg / M cubic) ↘

0.00025 M2 × 4000 m = 1 m3
Then 1 meter square meter x density is equal to the above answer!

The mass of copper wire is 8900kg, and the cross-sectional area is 10 cubic mm. What is the total mass of copper wire? What is the mass of copper wire of 20 cubic decimeter?
In fact, I think this question is strange. It seems that there is a mistake. PS how to correct it if there is a mistake

You have said that the total mass is 8900kg, and then you asked about the total mass? What's the total mass of the wire you didn't give me. Besides, you need to find out the density of copper. I forgot the formula. You can check it yourself,

The density of copper is 8.5x10 cubic kg / M cubic. A unit needs 2500m copper wire with a cross-sectional area of 3 cubic mm. How many kilograms of this copper wire do you need to buy?

66.75kg

When a section of aluminum wire is evenly stretched, its resistance will change____ Because of his_____ Getting bigger and bigger_____ It's getting smaller

When a section of aluminum wire is evenly stretched, its resistance will change_ Big___ Because of his__ Length___ Getting bigger and bigger__ Cross sectional area___ It's getting smaller