Key relationship
FB=ρliquidgVsubmerged; W=ρobjectgVobject.
Physics · Class 11
Submerge a floating object
Mechanical Properties of Fluids
Buoyancy equals the weight of displaced liquid. At equilibrium a floating object displaces its own weight, rather than its whole volume. Objects denser than the liquid cannot float freely in this model.
Open the interactive experiment →Submerge a floating object
மிதப்பு விசை இடம்பெயர்ந்த திரவத்தின் எடைக்குச் சமம். மிதக்கும் பொருளின் எடை மற்றும் மிதப்பு விசை சமம்.
Key notes, relationships and model limits
Remember
Buoyancy equals the weight of displaced liquid. At equilibrium a floating object displaces its own weight, rather than its whole volume. Objects denser than the liquid cannot float freely in this model.
Common trap
A floating object does not usually displace its full volume.
Model limits
Uniform object, incompressible liquid, negligible air buoyancy. Submergence is imposed for the experiment; a freely floating object chooses the zero-net-force fraction when that fraction is ≤1.
What you will learn
Apply Archimedes principle and find a floating fraction.
Try the experiment
Try both scenarios, change one control, and predict the result before checking the graph and readouts.
Think of it this way
Change one input while keeping the others fixed, as you would in a controlled experiment.
Worked example
A 2 L object of density 600 kg/m³ weighs 11.772 N. At 60% immersion, water displaced is 1.2 L and buoyancy is 11.772 N.
Why this matters
The model connects submerge a floating object with an observable reading. Check the equation and assumptions before applying it.
Before you start
SI units · algebra · graph reading
Check your understanding
A 600 kg/m³ object floats in water. What fraction is submerged?
- All of its volume
- 0.6 of its volume
- 0.4 of its volume
Read the explanation
Balance weights: ρwaterVsub=ρobjectVobject, hence fraction=600/1000.
Course connection: Class XI Chapter 9. Consult the roadmap for CBSE, NEET, JEE Main and Advanced scope.