How to write that per that in mathematical terms?

In summary, the conversation discusses the mathematical equivalent of expressing a rate, such as meters per second, and the difference between using a fraction or an equation to represent it. It is not possible to use an equals sign in this context as the units do not match. Instead, the rate can be written as a fraction with matching units or described using words.
  • #1
Juwane
87
0
How to write "this per that" in mathematical terms?

What is the mathematical equivalent of saying, for example, meters per second?

If we want to say that something moves with the rate of 50 meters per 30 seconds--do we write this as a fraction or as an equation, or we can write as both?

I mean what is the difference between saying "50 m/30 sec" and "50 m = 30 sec"? I'm confused.
 
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  • #2


You would write:

[itex]1 + \frac{2}{3} \; \frac{m}{s}[/itex] or [itex]\frac{5}{3} \; \frac{m}{s}[/itex] or [itex]\frac{50}{30} \; \frac{m}{s}[/itex]

or in indefinite form:

[itex]1.6... \; \frac{m}{s}[/itex]

The general syntax being, "change in y over change in x":

[itex]\frac{\delta y}{\delta x}[/itex]

"50 m = 30 s" is not possible, = indicates equality, and 50 m is NOT equal to 30 s.
 
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  • #3


tuoni said:
You would write:

[itex]1 + \frac{2}{3} \; \frac{m}{s}[/itex] or [itex]\frac{5}{3} \; \frac{m}{s}[/itex] or [itex]\frac{50}{30} \; \frac{m}{s}[/itex]

or in indefinite form:

[itex]1.6... \; \frac{m}{s}[/itex]

The general syntax being, "change in y over change in x":

[itex]\frac{\delta y}{\delta x}[/itex]

"50 m = 30 s" is not possible, = indicates equality, and 50 m is NOT equal to 30 s.

How can we I set the fraction to an equal something? Can I say something like:

[itex]\frac{50 m}{30 s} = \frac{5}{3}[/itex]
 
  • #4


You cannot. Since the units don't match on each side of your equation, the equation is nonphysical.

You can say [tex]\frac{50m}{30s}=\frac{5m}{3s}[/tex]
 
  • #5


Juwane said:
I mean what is the difference between saying "50 m/30 sec" and "50 m = 30 sec"? I'm confused.

Compare these two sentences.

"The man walked over the hill."

"The man with no hair."

The first one is a sentence. The second isn't.

The same is true of "50m = 30sec" and "50 m/30 sec". The equals sign makes a statement about two values. It says the value on the left is equal to the value on the right. The second one is just a value... with no equals sign. The equals sign is the verb. Without one, you just have a meaningless noun.

What you want to express can't be put into symbols. Use words to describe it: "the man ran 50m in 30sec" or "His velocity was 50m/30sec".
 
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Related to How to write that per that in mathematical terms?

1. What is the general format for writing a mathematical expression?

The general format for writing a mathematical expression is to use symbols and operators to represent the quantities and relationships in the expression. This typically involves using variables, numbers, and mathematical symbols such as +, -, x, and =.

2. How do I properly define and use variables in mathematical expressions?

Variables are used to represent unknown quantities in a mathematical expression. When defining a variable, it is important to clearly state what the variable represents and use a consistent notation throughout the expression. For example, if x represents the number of apples, it should be used as x throughout the expression.

3. What is the order of operations in mathematical expressions?

The order of operations in mathematical expressions is a set of rules that dictate the order in which operations should be performed. The standard order of operations is Parentheses, Exponents, Multiplication and Division (from left to right), and Addition and Subtraction (from left to right).

4. How do I write fractions and exponents in mathematical expressions?

Fractions can be written using a horizontal line between the numerator and denominator, or using the division symbol (÷). Exponents can be written using the caret (^) symbol, or by using parentheses and writing the exponent as a superscript. For example, 3/4 can be written as 3 ÷ 4 or 3/4, and 5² can be written as 5^2 or (5)^2.

5. Are there any common mistakes to avoid when writing mathematical expressions?

Yes, some common mistakes to avoid when writing mathematical expressions include forgetting to use the correct order of operations, not clearly defining variables, and using incorrect symbols or notation. It is important to carefully check your work and make sure all symbols and operations are accurate and clear.

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