## 2008-05-04

### What Causes Buoyant Force?

The difference between the forces acting on the UPPER surface and the LOWER surface is the net force acting UPWARDS.

This net force is known as the BUOYANT FORCE.

Say, Force acting on the upper surface, F1 = P1 A
= h1pgA

Force Acting Underside, F2 = P2 A
= h2pgA

Net Force Acting Upwards = Buoyant Force
= Weight of Liquid Displaced = mg

Therefore, the buoyant force is equal to the weight of liquid displaced, which is in accordance with Archimedes' Principle

Anonymous said...

can u list down the meaning of the terms in bouyant's formula? i mean, what does 'h' mean...

Dean James said...

h1 is the distance from the TOP area of the object to the surface

P1 is pressure 1

p is density of liquid

g is gravity value

A is the total surface area.

h2 is distance from surface to BOTTOM part of the object

P2 is pressure exerted on the lower side

Anonymous said...

kindly give me an idea on how to solve the displaced fuild if there are two fluids act on it...

putimoo said...

The difference between the two pressures on the two faces of the object causes a resultant upward force,which is called the upthrust or the buoyant force.Because of the upthrust,a submerged object appears to lose weight in a liquid.