Dimensional Analysis: Period of a Pendulum to the length

AI Thread Summary
The discussion focuses on using dimensional analysis to demonstrate that the constant 2π is unitless in the formula for the period of a pendulum, T=2π√(L/g). Participants clarify that 2π is indeed unitless by definition and emphasize the importance of proper notation, particularly using parentheses to indicate that g is inside the square root. Simplifying the equation involves treating dimensionalities as algebraic variables, ultimately leading to the conclusion that the term can be expressed as dimensionless. The conversation highlights the need for careful manipulation of units to arrive at the correct understanding. Overall, the analysis confirms that 2π does not carry any units.
DracoMalfoy
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Homework Statement

Use unit analysis to show that the constant, 2π, is unitless.

Homework Equations



T=2π√L/g[/B]

The Attempt at a Solution



T= [T]
L= [L]
g= a= [L]/[T]^2= [L T^-2]

[T]= 2π√[L]/[L T^-2]
[/B]
Is this correct? I wasn't really sure how to do this. I'm using book examples to help me figure it out.
I already know that 2π is unitless by its own definition.
 
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DracoMalfoy said:
Is this correct?
It would be correct, as far as you have gone, if you to use parentheses to show that the "/g" is inside the square root.
Next, simplify, treating the dimensionalities as normal algebraic variables.
 
haruspex said:
It would be correct, as far as you have gone, if you to use parentheses to show that the "/g" is inside the square root.
Next, simplify, treating the dimensionalities as normal algebraic variables.

So.. cross out the Ls and leave T^2? It kinda confuses me with the lettering.
 
DracoMalfoy said:
So.. cross out the Ls and leave T^2? It kinda confuses me with the lettering.

[T]^2= 2π⋅ [T]^2
 
DracoMalfoy said:
[T]^2= 2π⋅ [T]^2

##\sqrt{[T]^2} = [T].##
 
DracoMalfoy said:
[T]^2= 2π⋅ [T]^2
One more simplification to make.
You can write a dimensionless term as [1].
 
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