Advertisements
Advertisements
प्रश्न
What is the cause of upthrust? At which point can it be considered to act?
Advertisements
उत्तर
A liquid contained in a vessel exerts pressure at all points and in all directions. The pressure at a point in a liquid is the same in all directions - upwards, downwards and sideways. It increases with the depth inside the liquid.
When a body is immersed in a liquid, the thrusts acting on the side walls of the body are neutralized as they are equal in magnitude and opposite in direction. However, the magnitudes of pressure on the upper and lower faces are not equal. The difference in pressure on the upper and lower faces cause a net upward force (= pressure x area) or upthrust on the body.
It acts at the centre of buoyancy.
APPEARS IN
संबंधित प्रश्न
What is the scientific name of the 'upward force' acting on an object immersed in a liquid?
A body while floating sinks deeper in a liquid of low density than in a liquid of high density.
Why do we feel light on our feet when standing in a swimming pool with water up to our armpits ?
How is the unit bar related to the S.I. unit pascal?
How does the pressure exerted by a solid and fluid differ?
Pressure at the free surface of a water lake is P1, while at a point at depth h below its free surface is P2. (a) How are P1 and P2 related? (b)Which is more P1 or P2?
- Calculate the height of a water column which will exert on its base the same pressure as the 70 cm column of mercury. Density of mercury is 13.6 g cm-3.
- Will the height of the water column in part (a) change if the cross-section of the water column is made wider?
A piece of wood if left under water comes to the surface. Explain the reason.
It is easier to lift a heavy stone under water than in air. Explain.
Assertion (A): The buoyant force on a submerged rigid object can be considered to be acting at the center of mass of the object.
Reason (R): In rigid body, force distributed uniformly through its volume can be considered to be acting at the centre of mass of the body.
