Question

6. The weights of a stone were 60g, 50g & 45g When it was weighted by immersing in three different liquids. If these liquids were saline water, freshwater and coconut oil, which might be 60 gwt. Justify your answer​

Answer 1

Given info : The weights of a stone were 60g, 50g & 45g When it was weighted by immersing in three different liquids. and these were saline water, fresh water and coconut oil.

To find : which might be 60 gwt ?

solution : we know, buoyancy force = mg × ρ_(liquid)/ρ_(object)

it means, buoyancy force is directly proportional to density of liquid. so, higher the density, higher buoyancy force will be.

but loss of weight will be minimum, if the buoyancy force will be minimum.

So, to get minimum loss of weight, we need to put stone in a liquid of lowest density.

here, density of coconut oil is lowest i.e., 0.91 < 0.997 [ fresh water ] < 1.023 [saline water ]

therefore the weight of stone was 60 gwt in coconut oil.