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Post by striker16 on Dec 15, 2011 18:04:04 GMT 1
I don't understand the concept of specific gravity since, we are told, gravity exerts an equal force on bodies of various masses. For example, when a stone and a feather are dropped from a tower the time they take (in theory) to reach the ground is equal. So, what's specific gravity all about?
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Post by principled on Dec 15, 2011 19:28:51 GMT 1
Striker, I suspect you know the answer! But just in case, specific gravity is no more and no less than relative density.
P
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Post by striker16 on Dec 15, 2011 20:23:58 GMT 1
Striker, I suspect you know the answer! But just in case, specific gravity is no more and no less than relative density. P No, I didn't know but now I understand. TYVM. But now I'm wondering why we need to know. Any idea?
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Post by principled on Dec 16, 2011 12:11:52 GMT 1
Striker, There are many uses as RD. for example it can be used to determine the buoyancy of something in a liquid. Taking at its simplest-day to day- level, You pop down to your local garage to have your antifreeze checked. The guy takes a sample in a hydrometer and notes the position of the float inside. The higher it floats, the more antifreeze in the solution. You can apply this to all solutions (including beer and wine!!!), so it is a very useful measuring mechanism for solution concentrations. Obviously, if you have equal amounts of two substances, one of known RD and the other unknown, then by measuring the the RD you can determine the RD of the unknown substance. Wiki has some good examples and by reading the section on uses I have discovered that geologists and mineralogists use it all the time. I hadn't considered this use before.(we live and learn) en.wikipedia.org/wiki/Relative_density#Uses
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Post by jonjel on Dec 16, 2011 12:51:37 GMT 1
And let us not forget that fat people float while the skinny ones sink.
I am not sure if RD can be applied to brain function. maybe that is a density with a different connotation.......
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Post by striker16 on Dec 16, 2011 12:55:19 GMT 1
Thanks principled, I've learnt something new.
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