Question

a piece of alloy has a mass 86g in air and 73g when immersed in water find its volume and density​

Answer 1

Answer:

Let me rephrase that in better form. g is a measure of mass. newton is a measure of weight.86 g = 0.086 kg which weighs about 0.86 newton. When immersed in water while suspended, its weight falls to 0.73 newton. Where did that weight go to?

The water level rose, certainly and the water beaker would now weigh 0.13 newton more. It was an Archimedean observation that the weight change indicates the weight of an equivalent volume of water.

It’s a quick approximation that water weighs 1000kg X 10N/kg = 10000N per cubic meter, or in more handy terms 0.01 N / cm^3.

So thanks to Archimedes we can say with confidence, the object suspended in water has a volume like that of the water displaced 13 cc and has a mass of 86g instead of 13 g

so its relative density is 86/13 = 6.62. We can now refer to a table of densities, and guess that the material is similar to tellurium or tin