Floating Bodies

Any body, which is able to swim on the fluid surface can be called floating body. For instance, you might have already come across many ships, which have been made up of steel materials, floating over the sea or ocean water. However, the design in which these ships are being constructed also plays a major role when it comes to floating, as a simple steel material will sink in the water. The design should be in such a way that it should be very much able to enclose the required quantity of air to make it a floating body. As a result of the design, the average density of water will be more than that of the ship and thereby making the ship to easily float over the water. The concepts like equilibrium, the stability etc, will make this topic in the physics as interesting one.

Floatation Law

Consider that you are placing a piece of wood or other floating body over the water. When the water displaced by the wooden piece reaches its own weight it starts floating freely over the surface of water, or else, it will sink. As a result, it will also lead to the study of the flotation principle.

Floatation Principle

The quantity of fluid, which is displaced by any floating body, will be equal to the weight of the same body.

There is also something called plimsol line, which plays a major role in the studies of floating body. A ship will start sinking until the weight of the same ship reaches equal to the quantity of upthrust on the ship. Well, the upthrust here is nothing but the water’s weight that the part of the ship, which is submerged, will displace. The seawaters density will not be the same in all parts of the world.

Questions:

• When does a body start floating?
• What is the upthrust of a body?