Archimedes' Principle: Why Objects Float, Sink, or Hover

Floatation and Archimedes' Principle

When an object is placed in a fluid, two opposing forces act on it:

(1) Gravity (F_g) pulls the object downward. (2) Buoyant force (F_b) pushes the object upward, caused by the fluid displaced.

As the object goes down, the buoyant force increases and keeps increasing until it balances the gravitational force. If F_b equals F_g, the object floats; if F_b is smaller, the object sinks.This is the essence of Archimedes’ Principle.

How to Use the Simulation

1/ Choose the object’s mass using the slider.

2/ Select the material (styrofoam, wood, ice) — each has a different density.

3/ Pick the fluid (gasoline, oil, water, seawater) or set its density with the slider.

4/ Watch the beaker update:

5/ Green arrow shows buoyant force F_b.

6/ Red arrow shows weight F_g.

Live Data shows exact force values and how much of the object is submerged.

7/ Hit ✨ Demonstrate Flotation to see the process unfold step by step.

Notice in the Simulation-

a/ As the body submerges, the upward buoyant force vector grows in size, directly proportional to the submerged volume.

b/ At the same time, more water is being displaced, which is the source of the buoyant force.

c/ The simulation highlights this with the green arrow (F_b) lengthening until it equals the red arrow (F_g).

This makes clear that buoyant force is not a fixed push but depends on how much of the object is under water