Q20 of 81 Page 273

A solid sphere of radius 5 cm floats in water. If a maximum load of 0.1 kg can be put on it without wetting the load, find the specific gravity of the material of the sphere.

Let the specific gravity of the material be “x”.

Therefore, the density of the material is,


Given, radius of the sphere is 5 cm.


Therefore, Volume of the sphere,


The mass of the sphere is thus, .


The total mass of the system is, —————(1)


And mass of the water displaced, —————(2)


From buoyant force, equation (1) and (2) are equal.



Solving for x, we get



The specific gravity of the material is 0.8.


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