Once back on dry land, your body feels heavy.
Buoyancy is the force in the water that makes you feel light when you are in the water.

Background Information
Some objects, when placed in water, float, while others sink, and still others neither float nor sink. This is a function of buoyancy. We call objects that float, positively buoyant . Objects that sink are called negatively buoyant . We refer to object that neither float nor sink as neutrally buoyant .

There are three types of buoyancy

positive buoyancy -objects with positive buoyancy float

neutral buoyancy - neutral buoyancy objects neither float nor sink - they are suspended in the middle

Negative buoyancy - objects with negative buoyancy sink

 

id: arygllbp

The idea of buoyancy was summed up by Archimedes, a Greek mathematician, in what is known as Archimedes Principle: Any object, wholly or partly immersed in a fluid, is buoyed up by a force equal to the weight of the fluid displaced by the object. From this principle, we can see that whether an object floats or sinks, is based on not only its weight, but also the amount of water it displaces . That is why a very heavy ocean liner can float. It displaces a large amount of water.

Exercise 4.3: Create a Boat

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