Force and Pressure

Archimedes Principle Archimedes Principle states that when a body is wholly or partially immersed in a fluid it experiences an upthrust equal to the weight of the fluid displaced. Upthrust/Buoyant force is an upward force exerted by a fluid on an object immersed in it. Mathematically, we write F=ρVg      F = Upthrust/Buoyant Force  … Read more

Hydraulic Braking System In most vehicles, a hydraulic system is used in the braking system, as shown in the figure below. Usually, a disc brake is used in the front wheel of a car while a drum brake is used in the back wheel of a car. Working Mechanism of Hydraulic Brake When the brake … Read more

Example 1:In a hydraulic system the large piston has a cross-sectional area A2 = 200 cm² and the small piston has cross-sectional area A1 = 5 cm². If a force of 250 N is applied to the small piston, what isa. the pressure exerted on the small pistonb. the force F, produced on the large … Read more

Pascal’s Principle Pascal’s principle states that in a confined fluid, an externally applied pressure is transmitted uniformly in all directions. Pascal’s principle is also known as the principle of transmission of pressure in a liquid. Q & A Q: Suggest an experiment to prove Pascal’s Principle. A: When the plunger is pushed in, the water … Read more

The pressure of the gas trapped in a capillary tube depends on the position of the tube. Figure below shows the pressure of the gas when the capillary tube is horizontal, vertical and vertically upside down. Example: Figure above shows 3 identical capillary tubes with one end sealed and containing a column of mercury. PA, PB and PC are the … Read more

Manometer A manometer is a U-shape tube filled with some liquid (usually mercury). Manometer is a device used to measure gas pressure in a container. The pressure of the gas is equal to the sum of the atmospheric pressure and pressure due to the column of liquid. Pgas = Patm + Pliquid Note: There are a … Read more

A Bourdon gauge is used to measure to gas pressure in a container. There are 3 important components in a Bourdon gauge the copper tube the lever system the pointer Working Mechanism of a Bourdon Gauge When the gauge is connected to a gas supply, the gas pressure will straighten the copper tube. The copper … Read more

Instruments Used to Measure Gas Pressure The pressure of the gas in a container can be measured by using Bourdon gauge Manometer In SPM, almost all calculation question about using instruments to find gas pressure in a container are related to manometer. Therefore it’s important for you to know the concept behind this instrument. For … Read more

Anaroid Barometer The anaroid barometer is usually used to measure altitude, which is named as altimeter. Q & A Q: Explain why the barometer can be used to measure altitude. A:The atmospheric pressure is inversely proportional to the altitude. The altitude can be determined from the atmospheric pressure. Q & A Q: Why a simple … Read more

Fortin Barometer The Fortin barometer is an improved version of the simple mercury barometer. The barometer tube is encased in a brass frame. This enables it to be carried around easily. Vernier scale is used for taking reading for extra accuracy. Q & A Q: What is the advantages of a Fortin Barometer over a … Read more