﻿ Calculate the force required to take away a flat circular plate of radius 5cm and mass 2gm from the surface of water. The surface tension of water is 72 dyne/cm. from Physics Mechanical Properties of Fluids Class 11 Manipur Board

## Chapter Chosen

Mechanical Properties of Fluids

## Book Store

Currently only available for.
CBSE Gujarat Board Haryana Board

## Previous Year Papers

Download the PDF Question Papers Free for off line practice and view the Solutions online.
Currently only available for.
Class 10 Class 12
Calculate the force required to take away a flat circular plate of radius 5cm and mass 2gm from the surface of water. The surface tension of water is 72 dyne/cm.

Given,
Radius of the circular plate, r = 5 cm
Mass, m = 2 gm
Surface tension of water, T = 72 dyne/cm

$\therefore$ Weight of plate is, W = mg=2 x 980 = 1960 dyne

The circumference of circular plate is given by, $\phantom{\rule{0ex}{0ex}}\mathrm{\ell }=2\mathrm{\pi r}=2\mathrm{\pi }×5=31.4\mathrm{cm}$

The down pull on plate due to surface tension is given by,

Therefore, total force required to take plate away from water surface is,

F=W+f

=1960+2260.8

=4220.8 dyne

167 Views

Why solids have definite shape while liquids do not have definite shape?

Solids: Intermolecular forces are very strong and thermal agitations are not sufficiently strong to separate the molecules from their mean position. Solids are rigid and hence they have definite shapes.
Liquids: In liquids intermolecular forces are not sufficiently strong to hold the molecules at definite sites, as a result they move freely within the bulk of liquid, therefore, do not possess definite shapes. Liquids take the same shape as that of the container.
977 Views

What is fluid?

Any material that can flow is a fluid. Liquids and gases are examples of fluid.

976 Views

What is hydrodynamics?

Hydrodynamics is the branch of science that studies about the force exerted by the fluids or acting on the fluids.
799 Views

Do intermolecular or inter-atomic forces follow inverse square law?

No. Intermolecular and inter-atomic forces do not obey the inverse square law.
1257 Views

What is hydrostatics?

Hydrostatics is the branch of fluid mechanics that studies incompressible fluids at rest. The study of fluids at rest or objects placed at rest in fluids is hydrostatics.
854 Views