What is Upthrust ?

Ans : In the presence of a gas or fluid, an item either sinks or floats depending on its density.  whenever an object floats  the force that causes the object to float is upthrust force, which is exerted by the liquid or gas on the object that we are attempting to immerse. Depending on the relative density of the object and the density of the fluid in which we are immersing, the object will sink or float, and this is a concept that is observed is called Buoyancy.