When body sink in liquid ? Explain ?
A sphere of solid material of relative density $9$ has a concentric spherical cavity and floats having just sinked in water. If the radius of the sphere be $R$, then the radius of the cavity $(r)$ will be related to $R$ as :-
A boy has $60\, kg$ weight. He wants to swim in a river with the help of a wooden log. If relative density of wood is $0.6$, what is the minimum volume of wooden log? (density of river water is $1000\, kg/m^3$)
Acork of density $0.5\ gcm^{-3}$ floats on a calm swimming pool. The fraction of the cork’s volume which is under water is ........ $\%$
Given below are two statements: one is labelled as Assertion $A$ and the other is labelled as Reason $R$
Assertion $A:$ When you squeeze one end of a tube to get toothpaste out from the other end, Pascal's principle is observed.
Reason $R:$ A change in the pressure applied to an enclosed incompressible fluid is transmitted undiminished to every portion of the fluid and to the walls of its container.
In the light of the above statements, choose the most appropriate answer from the options given below
What is the direction of buoyant force ?