1: 3 is mortar mass ratio or volume ratio

1: 3 is mortar mass ratio or volume ratio

Is 1:3 mortar mass ratio or volume ratio
A: 1:3 is the volume ratio. Why do you say that? Can the ratio in the figure below form 1:3? The mix proportion in JGJ / t220-2010 is composed of cement kg / M & # 179;: sand kg / M & # 179;: water kg / M & # 179
&It's not 1:3, but 1:3.9. You can imagine that it's volume ratio. If it's mass ratio, it's 1:3.9

1: Volume ratio or mass ratio of 0.3:2.5 mixed mortar plastering

Volume ratio
For example: 1:2.5 cement mortar
It is the volume ratio of cement and sand in mortar volume mix proportion!

How to convert volume ratio into mass ratio? For example!

Example: how to convert the volume ratio of 1:3 cement mortar into mass ratio
The volume weight of cement and sand is reduced by 1; 3 generations
For example: the bulk density of cement is 1200kg / m3; the bulk density of medium sand is 1600kg / m3
(1 * 1200kg / m3) / (3 * 1600kg / m3) = 1200 / 4800 = 1 / 4
1: 3 cement mortar, the volume ratio converted into mass ratio is 1:4

How are volume and mass units converted?
For example, 1 liter =? Kg / g
1 liter =? Kg / g, etc

It depends on the density of the material. Mass = volume * density
For example, if the density of water is 1kg / L, then the mass of 1l water is 1L * 1kg / L = 1kg

Find out the unit "1"
1. The number of boys is two fifths of the class. 2 two thirds of the white rabbits are as many as the grey rabbits. 3 on average, every school gets four fifths of the total number of books per hour. A bag of rice eats one eighth and a pot of oil uses three fifths

1. The number of boys is two fifths of the class
1 is the number of students in the class
Two thirds of white rabbits are as many as grey rabbits
One is the number of white rabbits
On average, he did two-thirds of the whole journey per hour
One is the whole journey
Each school gets four ninths of the total books
1 is the total number of books
One eighth of a bag of rice
One is a bag of rice
Three seventh of a pot of oil is used
1 is a pot of oil

Insert two numbers between 4 and 12, so that the first three numbers are in equal proportion sequence, and the last three numbers are in equal difference sequence

4 x y 12；
x²=4y;
x+12=2y;
x²-2x-24=0;
(x-6)(x+4)=0;
X = 6 or x = - 4;
Y = 9 or 4;
6,9 or - 4,4, respectively;

Flexible use of knowledge to calculate skillfully -95-100．

4000-5-10-15-… -95-100=4000-（5+10+15+… +Number of items = (100-5) △ 5 + 1 = 204000-5-10-15 - -95-100，=4000-（5+10+15+… +100），=4000-[（5+100）×20÷2]，=4000-1050，=2950．

Isosceles trapezoid ABCD, diagonal ad parallel BC, AD + CB = 10 AC, vertical BD height

How about the diagonal? Make it clear

(1) It is defined that △ is a new operation symbol, and a △ B = A & # 178; - a × B + A-1, for example, 2 △ 3 = 2 & # 178; - 2 × 3 + 2-1 = - 1
Please try to find the value of 4 △ 5 according to the above rules. (2) we know that | x | = 3, (y + 1) & # 178; = 4, and XY ＜ 0 to find the value of X-Y

4△5=4×4－4×5＋4－1＝－1
①X＝3　　　Y＝－3　　　　　X－Y=6
②X＝－3　　Y＝1　　　　　　X－Y=－4

It is proved in higher algebra that a and B are square matrices of order n. if AB = Ba and a has n different eigenvalues, it is proved that B is similar to diagonal matrix

Let a be the eigenvalue of a and X be the corresponding non-zero eigenvector, then ABX = Bax = B (AX) = B (AX) = a (BX). This shows that BX is also the eigenvector of a corresponding to the eigenvalue a, and BX and X are the corresponding eigenvectors of A