more applied maths questions

Job ID: 35199134

Budget: $10 – $30 USD

I have a 1000kg weight that is hanging from a pulley one kilometer above the sea
I have another pulley at the bottom of the sea
The sea is 1 km deep
There is a rope holding the weight going over the pulley in the air
This rope passes under the pulley at the bottom of the sea
The is a buoy attached to the end of the rope so that as the buoy rises the 1000 kg weight is raised higher in the air by the rope
Assuming the rope has no weight
Assuming the buoy has no weight
How big in volume does the buoy have to be