Chapter 9: Mechanical Properties of Fluids
NCERT Class 11 Physics, Part II, Chapter 9. 8 lessons, 17 narrated 3D videos, 11 simulations and 16 quiz questions, following the textbook section by section.
- Pressure and its variation with depthLiquids and gases can flow, so we call them fluids. A fluid has no fixed shape of its own: pour water from a lota into a glass and it takes the shape of the glass.
- Atmospheric and gauge pressureWe live at the bottom of an ocean of air, many kilometres deep. The weight of the air above each square metre of ground pushes down on it. That is atmospheric pressure.
- Pascal’s law and hydraulic machinesFill a plastic bottle with water and poke small holes all around it. Squeeze the bottle. Water squirts out of every hole, up, down and sideways, all with the same…
- Streamline flow and continuitySo far our fluids have been at rest. Now let them move. The study of fluids in motion is called fluid dynamics.
- Bernoulli’s principleWater flows through a pipe that changes in width and climbs uphill. At each point it has a pressure, a speed and a height. In 1738 Daniel Bernoulli found how these three…
- Viscosity and Stokes’ lawTip a spoon of water and a spoon of honey. The water runs off at once; the honey oozes out slowly. Honey resists flowing much more. We say it is more viscous.
- Surface tension and surface energyA pond skater walks on water without sinking. A dry steel needle, laid gently on water, floats. Rain falls in round drops. The surface of a liquid seems to behave like a…
- Angle of contact, drops and capillary risePut a drop of water on a clean glass plate: it spreads out into a thin patch. Put a drop of mercury on the same plate: it stays a round bead. Water on a lotus leaf also…