Home
Class 12
PHYSICS
A circular plate of radius 4 cm and weig...

A circular plate of radius 4 cm and weight W is made to rest on the surface of water. If a minimum pull of W + F is required to clear the plate off the water surface then find F. Given surface tension of water `S_(w) = 0.072 N m^(-1)`

Text Solution

Verified by Experts

Radius of the plate = 4 cm = 0.04 m
The downward forces acting on the plate : weight W and force due to surface tension F
`:. `Required force, F = `S_(w)` x circumference of the plate
`S_(w) xx 2nr`
`0.072xx2xx7ixx0.04`
0.018 N
Promotional Banner

Similar Questions

Explore conceptually related problems

The minimum force required to separate a light glass plate of perimeter 5m from a water surface is (Given surface tension of water = 70 xx 10^(-3) N/m)

A platinum wire ring of radius 2.5 cm floats horizontally on the surface of water . A vertically force of 0.022 N is required to detach the ring from the surface of water . Then surface tension of water is

A rectangular glass plate of dimensions 5 cm xx 4 cm is placed flat on the surface of water. Find the downward force on the plate due to surface tension. Given surface tension of water = 0.073 N m^(-1)

A rectangular plate of dimension 6 cm xx 4cm and thickness 2mm is placed with its largest face flat on the surface of water. Find the downward force on the plate due to surface tension. Surface tension of water is 7.0 xx 10^(-2)Nm^(-1) .

Calculate the amount force required to take away a flat plate of radius 5 cm from the surface of water . Given surface tension of water = 72 "dyne"" "cm^(-1).

The length of needle foating on the surface of water is 1.5 cm the force in addition to its weight required to lift the needle from water surface will be (surface tension of water =7.5N//cm )

A small piece of wire of length 4 cm is floating on the surface of water. If a force of 560 dynes in excess of itss apparent weight is requried to pull it up from the surface find the surface tension of water.

A rectangular plate of dimensions 6cm xx 4 cm and thickness 2 mm is placed with its largest face flat on surface of water . (i) What is the downward force on the plate due to surface tension ? Surface tension of water =7.0 xx10^(-2) "Nm"^(-1) (ii) If the plate is placed vertical so that the longest side just touches the water surface, find the downward force on the plate.

Calculate the pressure inside a raindrop of diameter 2 mm [ surface tension of water = 0.072 N/m]