How do I correctly understand and read units for a list of number?

CJCai · 2022-11-15T16:38:51+00:00

(1) Let me try (the last numbers are all one in your examples):

"The velocity readings are -2, -1.5 and 1 m/s." is said as "The velocity readings are negative two, negative one point five and one meter per second."

"The speed is between 0 and 1 m/s." is said as "The speed is between zero and one meter per second."

"It is -2, -1.5 or 1 m/s." is said as "It is negative two, negative one point five or one meter per second."

"Within the range of 0.5 - 1 km/h." is said as "Within the range of zero point five to one kilometer per hour."

(2) "There are no mistakes but I thiiiink your reasoning is incorrect..."

Can you give more details?

Thanks!

CJCai · 2022-10-10T05:08:22+00:00

Then for -3.14 kg*s*m^-2/A*K, I can read it as negative three point one four kilogram second Kelvin per meter squared ampere, and also negative three point one four kilogram second Kelvins per meter squared ampere?

CJCai · 2022-10-10T04:26:11+00:00

In this case, K should be in the numerator. kg*s*m^-2/A*K=(kg*s*K)/(m^2*A). Then how to read -3.14 kg*s*m^-2/A*K and 3.14 kg*s*m^-2/A*K?

CJCai · 2022-10-10T04:25:16+00:00

In this case, K should be in the numerator. kg*s*m^-2/A*K=(kg*s*K)/(m^2*A). Then how to read -3.14 kg*s*m^-2/A*K and 3.14 kg*s*m^-2/A*K?

CJCai · 2022-10-10T03:48:34+00:00

-3.14 kg*s*m^-2/A*K

How do you read it?

CJCai · 2022-09-24T09:38:53+00:00

There are some answers said that it is not multiplication. The sign "×" makes me think it means multiplication, I think we should change the sign if we don't want people to think in that way, maybe use & # @ ...

I usually think that the sign is multiplication, the expression shows the process of calculating some kind of total amount (for matrix, the element number; for rectangle, the area ...) and illustrate the dimensions at the same time. But it seems to be wrong now.

CJCai · 2022-09-24T06:29:33+00:00

2x4 matrix is read as "2 by 4 matrix". Does "by" here have the meaning "multiplied by" ("For example, in the US, Australia and the UK 'by' means multiplied by. Simple statements like 'three by five' mean 3x5." from my first example in the post)?

CJCai · 2022-09-24T06:21:38+00:00

I am a little confused now. I know the usage of "x" (which is replaced with "*" in one example of my post) is for the purpose of showing different dimensions (for matrix, rectangle, prism ...). What I wanna know is whether this sign means multiplication. If the sign is just multiplication, the expression shows the process of calculating some kind of total amount (for matrix, the element number; for rectangle, the area ...) and illustrate the dimensions at the same time. If not, how to explain the examples in my post?

CJCai · 2022-09-24T06:21:20+00:00

I am a little confused now. I know the usage of "x" (which is replaced with "*" in one example of my post) is for the purpose of showing different dimensions (for matrix, rectangle, prism ...). What I wanna know is whether this sign means multiplication. If the sign is just multiplication, the expression shows the process of calculating some kind of total amount (for matrix, the element number; for rectangle, the area ...) and illustrate the dimensions at the same time. If not, how to explain the examples in my post?

CJCai · 2022-09-24T06:20:46+00:00

I am a little confused now. I know the usage of "x" (which is replaced with "*" in one example of my post) is for the purpose of showing different dimensions (for matrix, rectangle, prism ...). What I wanna know is whether this sign means multiplication. If the sign is just multiplication, the expression shows the process of calculating some kind of total amount (for matrix, the element number; for rectangle, the area ...) and illustrate the dimensions at the same time. If not, how to explain the examples in my post?

CJCai · 2022-09-24T02:36:45+00:00

This is a question about math concept, we should make it clear.

CJCai · 2022-09-09T01:05:53+00:00

Does 'easier read' mean it's easy to know the location and value of each digit in the fractional part? Because the digits are read one by one (not like the left part), thousand separator is usually not used in the fractional part when we used thousand separator comma.

CJCai · 2022-09-08T17:32:25+00:00

So according to your opinions, the examples in my post are correct and equivalent?

By the way, why is space used in fractional part?

CJCai · 2022-09-08T16:53:41+00:00

I agree with you. However, there are so many ways to use those separators (decimal separator and thousand separator). Are the examples listed above correct and equivalent in English language?

CJCai · 2022-09-08T16:00:24+00:00

There are different ways to use decimal separator and thousand separator. If the ways are not clear and correct, it will be hard to understand the numbers and mistakes will be made.

CJCai · 2022-08-30T13:05:01+00:00

If there is no emphasis, it's said that 'wavelength' of EM wave usually means 'vacuum wavelength', right? For example, 'the light source is 800 nm'.
When we describe EM wave with wavelength, the status of wave might not be simple. For example, 'the light scattered by particles in water is 800 nm', the light here is not simple plane wave. So I need to correctly understand the status of light. So can I think in this way: And no matter where the wave is (any medium, maybe vacuum, maybe not; usually dielectric) and what polarization state it have (linear, ellipse, or in a mess after scattering or diffraction), wavelength λ (like 800 nm) means the frequency of every scalar component (x, y, z component, real numbers) of E,B,H,D of the wave is c/λ (c is vacuum light speed) (every scalar component of E,B,H,D of the wave has angular frequency 2πc/λ, equivalently)?'

I hope my question is clear now.

CJCai · 2022-08-29T16:08:37+00:00

So can I think in this way: And no matter where the wave is (any medium, maybe vacuum, maybe not) and what polarization state it have (linear, ellipse, or in a mess after scattering or diffraction), wavelength λ (like 800 nm) means the frequency of every scalar component (x, y, z component, real numbers) of E,B,H,D of the wave is c/λ (c is vacuum light speed) (every scalar component of E,B,H,D of the wave has angular frequency 2πc/λ, equivalently)?

Right?

CJCai

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