High school biology experiment, hydrochloric acid in different experiments, what is the concentration and role

High school biology experiment, hydrochloric acid in different experiments, what is the concentration and role

Dilute hydrochloric acid has the effect of dissociation when observing cells with microscope
Concentrated hydrochloric acid mixed with water is dilute hydrochloric acid ok... So simple

How to calculate the cylinder thrust formula?

Cylinder output f (KGF) = service pressure P (kgf / cm2) x sectional area a (cm2) - f friction resistance (KGF) f = P * A-F

The thrust formula of pneumatic cylinder
What's the relationship between the thrust of the cylinder and the stroke of the cylinder

The cylinder thrust has nothing to do with the cylinder stroke. The cylinder thrust has something to do with the stressed area. The long stroke will cause loss. You can look for the pneumatic industry standard

How to control the speed of the cylinder?

In engineering design, the selection of cylinder diameter can be found out from experience Table 1-1 according to its service pressure and theoretical thrust or pull force. For example, there is a cylinder whose service pressure is 5kgf / cm2 and thrust force is 132kgf when the cylinder is pushed out (cylinder efficiency is 85%). Q: how large is the cylinder diameter to be selected

Calculation formula of cylinder roundness and cylindricity
computing method

TYG-FGSF =FG

What is the thrust of SC250 * 700 cylinder?

In the model, 250 means that the diameter of the cylinder is 250mm = 25cm, area = 25 * 25 * 3.14g4 = 490.625 square cm. The pressure of the general industrial compressed air is generally 5 ~ 7kg / square cm, which can be multiplied by the area according to the actual pressure

Excuse me, the cylinder is not compressed. Does C mean that the cylinder pressure is 0?
The compression pressure of engine cylinder (hereinafter referred to as "cylinder pressure") refers to the gas pressure in the cylinder when the piston reaches the compression top dead center
Does not compressed C mean that the cylinder pressure is 0?
Does the compression ratio mean that the value on the cylinder gauge is 0?

Traditionally, no compression means no pressure, and the pressure is zero or close to zero; low compression pressure means insufficient pressure for compression ignition mixture!
The compression ratio is the ratio of the total volume of the cylinder to the volume of the combustion chamber!

At the end of the compression stroke, the gasoline engine is in the cylinder
A spark plug ignition B fuel injection C spark plug ignition followed by fuel injection D fuel injection followed by ignition

A spark plug ignition
Diesel engine B

There is a single cylinder gasoline engine with a speed of 800 revolutions per minute. The power stroke of the cylinder in one minute is less than 1
A 1600 times b 800 times C 400 times d 200 times please tell me the reason for your choice

C two stroke is one revolution, 800 times 2 is 1600 stroke, one of four stroke is work stroke, 1600 / 4 = 400 work stroke

A single cylinder four stroke gasoline engine has a cylinder diameter of 20cm, a piston stroke length of 30cm, a power stroke, an average gas pressure of 5 × 105Pa, and a flywheel speed of 360r / min. (1) calculate the output power of the gasoline engine; (2) if the gasoline engine consumes 70g gasoline per minute, calculate its efficiency. (the calorific value of gasoline is 4.6 × 107j / kg)

（1）p=9.0×l05Pa，S=πr2=3.14×（10cm）2=0.0314m2，∵p=FS The average pressure of gas to piston is: F = PS = 5.0 × lo5pa × 0.0314m2 = 15700n. ∵ s = 30mm = 0.03m, ∵ the work of gas to piston in one working stroke is: w = FS = 15700n × 0.3m = 4710j. The flywheel does external work once every two revolutions, so it needs to do external work 180 times when the flywheel rotates 360 cycles, ∵ the total work of gas to piston is: wtotal = w × 180 = 4710j × 180 = 847800j, and T = 1min = 60s, ∵ The power of gasoline engine is: P = wtotal, t = 847800j60s = 14130w. (2) according to the title, wtotal = Pt = 14130w × 60s = 847800j; qtotal = MQ = 0.07kg × 4.6 × 107j / kg = 322000j; so η = wtotal, q = 847800j322000j ≈ 26.3%; answer: (1) the output power of gasoline engine is 14130w; (2) if the gasoline engine consumes 70g per minute, its efficiency is 26.3%;