What is the formula for calculating the cross sectional area of a rectangular tube What is the formu

Know > Education Science > Admission > High School Entrance Examination Share to i Post Bar Add to Collection Solved.

Report Mathematics Basic Training Fifth Grade Volume 110 (Beijing Normal University Edition).

Mathematics Basic Training Fifth Grade Volume 110 Page 1 (Beijing Normal University Edition) Question 1 Gas Station: Xiaoxiao participated in the mathematics competition, a total of 25 questions, 4 points for 1 correct question, and 1 point for 1 wrong question. She scored 77 points.

Do you know how to answer questions with a smile? Is it possible for her to score 81 points? Why?

Asked by: Night Requiem - Level 2 Whistleblowing Xiaoxiao participated in a math competition, a total of 25 questions, 4 points for 1 correct question, 1 point for 1 wrong question, no points for not doing it, and no points for inverted points, she did all the questions and got 77 points. Do you know how to answer questions with a smile?

Is it possible for her to score 81 points? Why? It seems that there is a problem with this question, because Xiaoxiao has done all the questions, you can set it as the right x question, and if you get it wrong, you will get 4*x points for the correct question, and 25-x points will be deducted if you do it wrong, and the total score is:

4x-(25-x)=77

4x-25+x=77

5x=102 has no integer solution. Suppose Xiaoxiao did x questions correctly, did wrong y questions, and did z questions but didn't do z questions in the condition z=0

Then x+y+z=25 (1).

4x-y=77 （2）

There is no integer solution to this system of equations.

That is, if she does all the questions.

A 77-point scenario is unlikely.

If you smile and get 81 points.

Then 4x>=81, which means that x is at least 21

Then y is at least 3 (because 4*21-3=81).

At this time, z=1 means that there is a question that has not been done, and 21 of the 24 questions that have been done are correct and 3 are wrong).

This situation is also the only possibility: Suppose Xiaoxiao did x questions correctly, did it wrong, y questions, and did z questions but did not do z questions, and z=0 in the condition

Then x+y+z=25 (1).

4x-y=77 （2）

There is no integer solution to this system of equations.

That is, if she does all the questions.

It is impossible to score 77 points The theme of the building is wrong, it should be 75 points, not 77 points. The score of Xiaoxiao should be a multiple of 5! The landlord wrote the score wrong, it should be 75 points!

1+4＝5，75/5＝15，15+5＝20，25-20＝5。Because 81 5 is not an integer, it is impossible to score 81 points, unless he only did 24 questions and did 1 question without doing it.

I don't know about that, but others do.

Dude, you're having a lot of fun, hehe.

1. Calculate the area of the outer circle first: s1 = *r 2

2. Then calculate the area of the inner circle: s2= *1r 2

3. Then the cross-sectional area s is: s=s1-s2

4. The volume of steel pipe steel is: v=s * h

5. The weight of the steel pipe is: m= v

According to the connection method of the pipe end, the steel pipe can be divided into: plain pipe (pipe end without thread) and wire pipe (pipe end with thread).

Wire pipe is divided into: ordinary wire pipe and thickened wire pipe at the end of the pipe.

Thickened wire pipe can also be divided into: outer thickening (with external screw delay), inner thickening (with internal thread) and internal and external thickening (with internal and external thread) and other ground wire cutting pipes.

If the wire pipe is threaded according to the thread type, it can also be divided into: ordinary cylindrical or conical thread and special thread and other ground wire turning pipe.

In addition, according to the needs of users, the wire pipe is generally delivered with pipe joints.

Dear, I'm glad to answer for you, the formula for calculating the cross-sectional area of the pipe A: 1. First calculate the area of the outer circle of the laughing number: s1 = *r 22, and then calculate the area of the inner circle

s2 = *1r 23, then the cross-sectional area s is: s=s1-s2 for example, the cross-sectional area of the steel pipe with an outer diameter of 110 and an inner diameter of 102 is calculated as follows: 1. First calculate the area of the outer circle S1 = *110*110=12100 2, and then calculate the area of the inner circle:

s2 = *102 * 102 = 10404 3, the first cross-sectional area s is: s=s1-s2=12100 -10404 =1696 square millimeters = square centimeters.

Summary. Hello, 1.Calculate the compressive stress, which is the compressive stress generated by the vertical pressure acting on the cross-section of the square tube.

This is relatively simple, which is the pressure (in n) divided by the cross-sectional area of the square tube (in m squared). As long as the compressive stress is less than the allowable stress of the material.

2.The square tube is under pressure, and the stability should be calculated. Stability calculations are complex.

It depends on whether the connection is fixed at both ends or hinged at one end and the other end. It is estimated that you are not only using 1 column, so it can be easily calculated as a fixed connection at both ends. Simple calculation of critical pressure:

p=(4*n*pi^2*e*i)/[l/2)^2]。The number of n columns, pi 2 is the 2nd power of the beat, e modulus of elasticity, i moment of inertia, l column length.

Calculation of the bearing capacity of the square tube.

Hello, I am Teacher Little Bee, it is a pleasure to serve you, I will be you in five minutes.

Hello, 1.Calculate the compressive stress, which is the compressive stress generated by the vertical pressure acting on the cross-section of the square tube. This is relatively simple, which is the pressure (in n) divided by the cross-sectional area of the square tube (in m squared).

As long as the compressive stress is less than the allowable stress of the material. 2.The square tube is under pressure, and the stability should be calculated.

Stability calculations are complex. It depends on whether the connection is fixed at both ends or hinged at one end and the other end. It is estimated that you are not only using 1 column, so it can be easily calculated as a fixed connection at both ends.

Simple calculation of critical pressure: p=(4*n*pi 2*e*i) [l 2) 2]. The number of n columns, pi 2 is the 2nd power of the beat, e modulus of elasticity, i moment of inertia, l column length.

Calculate how much force this surface can experience at most.

Approximately 57 kg.

Hello, to calculate the bearing capacity of the square tube, you need to consider the specifications, materials, span, strength and so on of the square tube to calculate it specifically. Here, we need to clarify what is called "bearing capacity", the so-called bearing capacity is how much pressure can be withstood on the suspended span, such as the two ends of the 50*30* square tube are erected, and the span of 1 meter is suspended in the middle, and the 50*30* square tube can put multiple items on the span of 1 meter. In general, according to the design and calculation of the construction drawings, and then consider the specific use of which square pipe material (such as Q235 material or Q345 material, etc.), the square pipe material here needs to consider the specification thickness of the square pipe, the material performance of the square pipe, the production process of the square pipe, and the weld strength of the square pipe, etc., will affect the bearing capacity of the square pipe.

Therefore, without considering the above factors, we can use the following formula to calculate the bearing capacity of the square tube: m=pac l(m: bending moment, p concentrated force, a concentrated force distance from the support, c concentrated force from another support, l span, l = a + c) w = b * h * h * h 12 (only used for rectangular cross-sections) f = m w allowable stress (elastic tensile strength safety factor) of the material

The formula for calculating the tube is as follows:

1. Calculate the area of the outer circle first: s1 = *110 * 110 = 12100.

2. Then calculate the area of the inner circle: s2 = *102 * 102 = 10404.

3. The cross-sectional area s is: s=s1-s2=12100 -10404 =1696 square millimeters = square centimeters.

4. The volume of steel slag of steel pipe is: v = cubic centimeter.

5. The weight of the steel pipe is: m = v = g = kg.

Steel pipe production method:

1.According to the production method, seamless steel pipes can be divided into: hot-rolled seamless pipes, cold-drawn pipes, precision steel pipes, hot-expanded pipes, cold-spinning pipes and extruded pipes.

Seamless steel pipes are made of high-quality carbon steel or potato spring alloy steel, and are hot-rolled and cold-rolled (drawn).

2.Welded steel pipes are divided into furnace welded pipes, electric welded (resistance welded) pipes and automatic arc welded pipes because of their different welding processes, and are divided into two kinds of longitudinal welded pipes and spiral welded pipes because of their different welding forms, and round welded pipes and special-shaped (square, flat, etc.) welded pipes because of their end shapes.

In terms of manufacturing methods, it is divided into welded steel pipes for low-pressure fluid transportation, spiral seam welded steel pipes, direct coil welded steel pipes, welded pipes, etc. <>

Summary. Hello, dear, I am glad to answer for you: what is the formula for calculating the cross-sectional area of a round pipe:

r2-r2)=πr+r)(r-r)。Round pipe refers to steel with two ends open and hollow concentric cross-section, and its length is larger than the periphery. It can be used in pipelines, thermal equipment, mechanical engineering, petroleum geological drilling, vessels, chemical industry and special purposes.

In a plane, a closed curve formed by a moving point centered on a certain point and rotated around a certain length is called a circle. A circle has an infinite number of axes of symmetry. The set of points in the same plane whose distance to a fixed point is equal to a fixed length is called a circle.

A circle can be represented as a set, where O is the center of the circle and R is the radius. The standard equation for a circle is (x-a)?+y-b)?

r?where the points (a, b) are the center of the circle and r is the radius.

Hello, dear, I am glad to answer for you: what is the formula for calculating the cross-sectional area of a round pipe: *r2-r2)= r+r)(r-r).

The jujube round pipe refers to the steel that is open at both ends and has a hollow concentric cross-section, and its length is relatively large compared to the periphery. It can be used in pipelines, thermal equipment, mechanical engineering, petroleum geological drilling, vessels, chemical industry and special purposes. In a plane, a closed curve formed by a moving point centered on a certain point and rotated around a certain length is called a circle.

A circle has an infinite number of axes of symmetry. The set of points in the same plane whose distance to the fixed point is equal to the fixed length is called a round stool base. A circle can be represented as a collection of stalls, where o is the center of the circle and r is the radius.

The standard equation for a circle is (x-a)?+y-b)?=r?

where the points (a, b) are the center of the circle and r is the radius.

The outer diameter is 48, the wall thickness is thick, help me do the math.

Hello, dear, I am glad to answer for you to grasp the imitation: ring area: s big circle s small circle = (r 2 r 2) (r is the radius of the big circle of the big bucket, r is the radius of the small circle) r:

48 2=24r:【48-(segment sedan 2=:cross-sectional area of steel pipe:?