Question

What are uses of using specific gravity of an object?

Answer 1

Specific gravity is basically Relative density. It helps us to calculate density of a substance.

Answer 2

Ok, but in the "real world" how would this be helpful besides knowing if something sinks or floats in pure water? What are practical applications for SG?

Answer 3

specific gravity and density have a few uses. how much actual gold is there in an olympic gold medal. well, the mass per unit volume of the medal would not have the same density as gold, it would probably be nearer to that of silver which is what most of the medal seems to be made of. it's gold plated, in fact. This form of analysis is known as ASSAYING, and good old ARCHIMEDES was the greek bloke, after whom the "eureka can" is named got the idea. The fact that he lived on the mediterranean, with a load of ships hopping around may have helped him. If you assay a donald trump jewellery gift (someone did), you may find that it's worthless.
|A thing called a HYDROMETER is used to measure the SG of the fluid in a UK car battery. That's a measure of how much charge there is in the battery, and that sort of tells you whether or not the battery is flat or not. Mind you, if it doesn't start the engine, nor light the lights, then you can get the same sort of idea (i know this lot to my cost).

Answer 4

Then, there was a bloke who could have been called PLIMSOLL. He drew some, very big probably, horizontal lines on a boat which represented how far the boat would go down in the water as it was loaded up with cargo. I don't know the exact reason why, the idea of sinking - but NOT becoming submerged - is almost key to how most boats float. They sink until they've displaced enough water to float.
I think that the human body, being mostly water (yup, I'm a big drip, and now it's official) tends to float in water. But, I wouldn't try telling that to a novice swimmer.