Advertisements
Advertisements
प्रश्न
How does the friction arise between the surfaces of two bodies in relative motion?
उत्तर
The force of friction is arised by the interlocking of the irregularities of the two surfaces.
APPEARS IN
संबंधित प्रश्न
The free surface of a liquid resting in an inertial frame is horizontal. Does the normal to the free surface pass through the centre of the earth? Think separately if the liquid is (a) at the equator (b) at a pole (c) somewhere else.
Frictional force between solids operates even when they do not move with respect to each other. Do we have viscous force acting between two layers even if there is no relative motion?
If more air is pushed in a soap bubble, the pressure in it
Consider a small surface area of 1 mm2 at the top of a mercury drop of radius 4.0 mm. Find the force exerted on this area (a) by the air above it (b) by the mercury below it and (c) by the mercury surface in contact with it. Atmospheric pressure = 1.0 × 105 Pa and surface tension of mercury = 0.465 N m−1. Neglect the effect of gravity. Assume all numbers to be exact.
A metal piece of mass 160 g lies in equilibrium inside a glass of water. The piece touches the bottom of the glass at a small number of points. If the density of the metal is 8000 kg/m3, find the normal force exerted by the bottom of the glass on the metal piece.
A drop of oil placed on the surface of water spreads out. But a drop of water place on oil contracts to a spherical shape. Why?
A molecule of water on the surface experiences a net ______.
The wear and tear in the machine part is due to ______.
This model of the atmosphere works for relatively small distances. Identify the underlying assumption that limits the model.
The surface tension of boiling water is ______.
