First slide
Fluid statics
Question

A hollow sphere of volume V is floating on water surface with half immersed in it. What should be the minimum volume of water poured inside the sphere so that the sphere now sinks into the water? 

Moderate
Solution

When body (sphere) is half immersed, then Upthrust = weight of sphere

 V2×ρliq×g = V × ρ×g   ρ = ρliq2

When body (sphere) is fully immersed then,

Upthrust = weight of sphere + weight of water poured in sphere

 V × ρliq×g = V×ρ×g + V'× ρliq×g

 V ×ρliq = V × ρliq2+V'×ρliq V' = V2

Get Instant Solutions
When in doubt download our app. Now available Google Play Store- Doubts App
Download Now
Doubts App