### Theory:

Buoyant force:

Whenever an object is thrown inside a liquid (water) based on the buoyant force of the liquid, the object will float or sink. If the weight of the object is greater than the buoyant force of water, the object will sink inside, if the weight of the object is lesser than the buoyant force of water, the object will float over the liquid. Thus, the upward force exerted by the liquid on the objects floating is called buoyant force. The same applies to gases as well.

$\begin{array}{l}\mathit{weight}\phantom{\rule{0.147em}{0ex}}\mathit{of}\phantom{\rule{0.147em}{0ex}}\mathit{the}\phantom{\rule{0.147em}{0ex}}\mathit{object}\phantom{\rule{0.147em}{0ex}}>\phantom{\rule{0.147em}{0ex}}\mathit{buoyant}\phantom{\rule{0.147em}{0ex}}\mathit{force}\to \phantom{\rule{0.147em}{0ex}}\mathit{object}\phantom{\rule{0.147em}{0ex}}\mathit{sinks}\\ \mathit{weight}\phantom{\rule{0.147em}{0ex}}\mathit{of}\phantom{\rule{0.147em}{0ex}}\mathit{the}\phantom{\rule{0.147em}{0ex}}\mathit{object}\phantom{\rule{0.147em}{0ex}}<\phantom{\rule{0.147em}{0ex}}\mathit{buoyant}\phantom{\rule{0.147em}{0ex}}\mathit{force}\phantom{\rule{0.147em}{0ex}}\to \phantom{\rule{0.147em}{0ex}}\mathit{object}\phantom{\rule{0.147em}{0ex}}\mathit{floats}\end{array}$

The pressure exerted by liquids:

When we pour liquids in any container, tube or vessels, etc, the liquid will exert pressure on the bottom of the vessel as well as the sides of the container. This pressure exerted is called the static pressure. It can be defined as the force acting per unit area of the surface, on which the liquid is placed.
An instrument used to measure the difference in liquid pressure of the fluids in the same container, is called a manometer.

Activity:

Try it at home:

Take a water bottle and fill it with water. Now punch three holes, one in the upper side, one in the middle and other in the bottom side. If you observe the water flow, water from the bottom hole will exert more pressure than the water from the top side.

This is because the pressure exerted by liquids increases with an increase in depth.