Define thrust and pressure. State and explain Archimedes’ principle. Give the relation between the buoyant force and the weight of a body for a floating body.
Answers
This is the question from class 9 cbse board from the lesson gravitation.
Answer :-
(1) Thrust - Force exerted by an object perpendicular to the surface is called thrust.
(2) pressure - it is a thrust or force unit are on a surface.
Archimedes principle states that:-
when a body is immersed fully or partially in fluid ,it experiences an upward force which is equal to the weight of the fluid displaced by it.
Relationship between buoyant force and weight of the body for a floating body.
weight of a body = mg
where, m is the mass of a body and g is the acceleration due to the gravity.
In case of floating body ,the net force should be zero(0).
As we know that buoyant force is equal to the weight of the body (whether liquid or fluid) .
Hence buoyant force is equal to the weight of the object = mg.