Who knows if the theoretical weight of 8mm pattern steel plate in GB / t3277-1991 is wrong?

Who knows if the theoretical weight of 8mm pattern steel plate in GB / t3277-1991 is wrong?

7 ~ 8mm should not be right at all. Conventional 2 ~ 4mm lentil type calculation is based on δ * 7.85 * 1.09

The formula for calculating the volume of cube and cylinder
Please don't use letters or words.

Cube v = a ^ 3 (the third power of side length a)
Cylinder v = sh (bottom area multiplied by height)
=πr^2×h

A formula for calculating the total area of a cube

S=6L*L

What are the angles of 3.6mm, 6mm.8mm.12mm
From the middle of the camera as a starting point, the degree of diffusion around?

3.6mm: about 90 degrees
6mm: about 60 degrees
8mm: about 45 degrees
12mm: about 35 degrees

The difference between 3.6 mm lens and 6 mm and 8 mm lens
How far can they all see? What are their angles
6 mm / 6 mm / 8 mm / 12 mm. How many degrees and meters can they see the facial features

It's just a matter of the size of the angle of view to see infinity!

What is the conversion relationship of adhesion unit: n / 25mm, N / 20mm, g / 25mm?
The conversion relation of these three units is troublesome to consult

To measure the peeling force of glue, the required pulling force for pulling a 25 mm wide spline is 1 N, so you can change it by yourself

There is 440kg copper ingot in a workshop, which needs to be pressed into 5 square meters of copper plate. If the copper weighs 8.8t per cubic meter, how about the thickness of this copper plate?

44 divided by 8. 8, the result is the volume of 440kg copper ingot
This volume divided by 5 square meters is the thickness
The result is 0.01 meters,
That's one centimeter thick

The specific gravity of steel with thickness of 0.8 mm and area of 1 square meter is calculated as 7.8, and the formula and answer are listed
The specific gravity is calculated according to the general specific gravity

0.8 mm = 0.08 cm 1 m2 = 10000 cm 2 7.8 × 10000 × 0.08 = 6240 (g)

How much copper is an ocean

This is a problem of currency value. In the past, the Qing government and the early government of the Republic of China adopted the silver standard system. The ocean was made of silver. It was the currency in circulation at that time, commonly known as hard currency. It was a bit like the panda gold coin now. However, with the increase of China's foreign reparations, the production of silver could not meet the needs of currency production, and the currency circulation was seriously insufficient, resulting in a sharp rise in currency value, Originally, 1 ocean Exchange 100 copper coins to 1 ocean exchange 3000 copper coins, and then buy 1 liter rice only 10 copper coins

How many kilowatts can 1.5 square meters copper bear

The allowable cut-off flow of continuous load is related to the place where the wires are used (such as open laying, concealed laying, iron pipe, plastic pipe), temperature, etc.; it is related to the types of wires (rubber wire, plastic wire). At present, most of the plastic wires are commonly used. If the wires are made of plastic pipes, and multiple wires (take 4 as an example) are in the same pipe, the temperature is not higher than 30 ℃, and the allowable load current is 12a, That's more than 2600 watts