Physics 10 gradePascal's law, atmospheric pressure Supplementary materials

Torricelli experiment

The method of measuring atmospheric pressure in 1643 was adopted by the Italian scientist E. Torricelli proposed. In his experiment, Torricelli used a glass tube 1 meter long, fixed at one end. The tube fill with mercury this open edge closed with your finger while standing, cast ten wide mercury in the container. After you remove your finger, all the mercury from the vessel does not overflow.

1.  Why has all mercury not been spilled?

2. The height of the remaining mercury column in the pipe was 760 mm. what conclusions can be drawn from this result?

3. Does the height of the class pole depend on the air temperature and latitude?

4. Offer a simple tool for measuring atmospheric pressure.

Hydraulic press Learn how the hydraulic press works and answer the following questions:

 1. General provisions what is called a hydraulic press?

 2. What is the design of the hydraulic press?

 3. Explain that the hydraulic press gives a powerful gain based on Pascal's law?

4. Explain the principle of operation of the hydraulic Jack and hydraulic brake.

According to the law of Pascal, the liquid or gas is supplied to the pressure unchanged in all directions. When Blaise Pascal discovered his law, he wondered how he could use it. He developed a device that is a hydraulic machine.

Hydraulic machines are machines whose principle of operation is based on Pascal's law.

The technique uses a variety of machines, whose activities are based on the equilibrium of liquids and the laws of motion. They are called hydraulic machines (from Greek.hydro-water, aulos-tube). For example: hydraulic brakes in cars, trucks and buses; hydraulic lifts for lifting heavy loads on tractors; hydraulic lifting chairs and other simple mechanisms. Because all of them use the force of fluid pressure.

On a simple hydraulic machine there are two mobile pistons with different cross-sectional area. The cylinders connected to each other are filled with liquid (oil).

 The cross-sectional area of the small piston is S1 and the large piston is S2. According to the law of Pascal, the fluid provides the pressure without changing the large piston. Therefore, the large piston is affected by the force F2. Now imagine this powerful:

If the cross-sectional area of the large piston is greater than the smaller, then the large piston acts as many times the greater force.

Hydraulic pressing machine, rolling is called hydraulic press. All of them use the force of fluid pressure. Application: modern, powerful hydraulic presses allow us to produce power 700000KN. Such presses are used in factories to give metal products the necessary shape and size

Hydraulic pump

Please read this information and answer the following questions:

1. General provisions What is the device the piston of a fluid pump?

2. What is the operating principle of the piston liquid pump?

3. What is the principle of operation of water supply?

 Atmospheric pressure is the pressure of gravity that affects the air column descending into a unit area of the earth.

The law of Pascal: the liquid or gas is supplied to the pressure unchanged in all directions.

Piston liquid pump  

Piston liquid pump consists of a cylinder, including a piston, tightly located on the walls. The piston has valves that open upwards, both in the lower part of the cylinder and in the lower part of the cylinder. The piston moves upwards, under the influence of atmospheric pressure, the liquid raises the lower valve and passes into the pipe. When lowering of the piston the fluid under the piston pushes the bottom flap and close. In addition, the water pressure opens the valve on the piston and the liquid penetrates into the space above the piston.

With the subsequent lifting of the piston, the liquid rises, the water drains from the mouth of the pipeline. In addition, when the piston is lifted, a new part of the liquid rises, which again rises with the piston lowering later.

Plumbing

The construction of the water pipeline is complex. With its help, from one city, village, industrial and agricultural enterprises there is a centralized water supply, provides the population with drinking water, meets the household needs of people working in factories.

Industrial water supply meets only industrial and technological needs. The principle of operation of the water supply system is as follows: in the upper part of the tower for water storage there is a large vessel. The tightened pipes connect to the house, consumers. The ends of the pipes in houses and apartments are closed with taps, the pressure on the tap is equal to the pressure of the water column at a height equal to the difference in the height of the tap and the free surface of the water in the tank. This pressure is important because the water tower is a city, village, etc. b. set at the highest point.The principle of using a water tower is based on Pascal's law, which takes place in contact vessels.

The first water pipelines were built several thousand years ago. In ancient Egypt, underground water was raised from deep wells and delivered to consumers through ceramic and wooden pipes. In ancient Rome, a complex water supply system was used. In Western Europe (Paris) in the late 17th century was built water supply with wooden pipes. In the XVIII century began construction of water supply in England. In Moscow, a centralized public water supply system was built in 1804. In 1933 the first wooden water supply system appeared in Almaty, and in 1935 planned construction of water supply systems with the use of reinforced concrete and ceramic pipes was started. Archaeological excavations show that in 10-12 centuries in Kazakhstan in the cities of Otrar and Taraz the water supply system from ceramics where the water supply system burned is constructed.