Strip a piece fo wire and weigh the different parts, then multiply by total length.

Silly me, I thought that figures like "300 mm2 single core" refer to the conductor, not total cable diameter.

1. You asked for formulas:

Mass = volume * density (density of copper is 8.96 g/cc)

Volume = area * length

Area = (Pi * diameter * diameter) / 4 (if you don't already know the area)

2. Or you could take a short piece of cable, say 1 meter, strip the insulation off and weigh the copper and the insulation separately so you know how many grams of each per meter and multiply by the length.

(I suspect you have 3 core cable. The weight you give is awfully high for single core.)

This table has weight of copper wire...

http://www.thelen.us/1wire.php

It's arithmetic, Ma'am. Multiply the conductor CSA by the length, and multiply that by the density. Even a silly English Polooceman can do that!

Regardless of the copper weight you will still have to dimension your buuldozer to pull out the cable's total mass and select a truck that can transport this total weight to the scrap merchants.

Working at night you need to be quick so you can't over estimate these things.

Pay the cops to stay at home.

Your question is not clear. You did not mention cable is for low voltage or Medium voltage.

However you have given the weight of low voltage 3-core cable but mention as single core cable weight.

Please find the cable data from one of the reputed manufacturing companies from Saudi Arabia for low voltage copper cables as per IEC-502 standard.

1. PVC/PVC insulated Unarmed Cables of size 300mm²

Weight of the three core cable with insulation = 10805Kg/km

Weight of the sing core cable with insulation = 3420Kg/km

1. PVC/PVC insulated Steel Wire Armed Cables of size 300mm²

Weight of the three core cable with insulation = 13500Kg/km

Weight of the sing core cable with insulation = 4065Kg/km

1. Copper Wire without insulation of size 300mm²

Weight of the single bare copper wire of 300mm² (without insulation) = 2627kg/km

Now, from the above data you can calculate whatever you want by using simple mathematics of addition and subtraction.