Late night gravity question

[Hogarth]

Something I’ve been pondering all day...

We know that 1kg of sugar raises the gravity of 1 litre of water by 340 points. ie from 1.000 to 1.340

But if you add 1kg of sugar to 1 litre water then that litre will now weigh 2kg, ie it will have doubled its mass, and hence its density. So why isn’t the gravity now 2.000?

Okay, I know that the sugar will also increase the volume of the water ... but surely not by enough to make that much difference.

Any clever people around who’d care to help me out? (Assume a high amount of 'density.' )

[Martin G]

Based on your figures;

Density = mass / volume

So

Volume = mass / density

In this case the mass is doubled but the density is 1.34 (34%) more so I recon;

2 / 1.34 = 1.5 times the volume, so in this case 1.5l. So I think your volume would be 1.5l after adding the sugar.

I may be wrong, but that's where my logic goes.

[Hogarth]

Brilliant! Thanks Martin. That makes perfect sense. Now I can relax.