Rearranging Formulas: Fairly simple but I'm very stuck

In summary, the student is trying to solve a homework equation and is struggling. He finds an equation similar to the one he was given, but realizes that the x^2 is not supposed to be there. He solves for g and gets the correct answer.
  • #1
Alexander8
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Homework Statement


Change the subject of the equation to (g)

Homework Equations


T = 2π√l/g x^2

86903828c3a4e638e3cbb27ab441fa67661bd89839ff26393fd3fbf0ab9e647a19972838.jpg


The Attempt at a Solution



In my attempt I've divided both sides by 2π for
T/2π = √l/g x^2

Then I decided to square both sides for

(T/2π)^2 = l/g x^2

Now I'm really not sure if what I've done so far is off or I'm on the right track?
I'm usually ok when it comes to this but for some reason this has caught me out
Any help would be greatly appreciated, thanks.
 

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  • #2
Alexander8 said:
Then I decided to square both sides for

(T/2π)^2 = l/g x^2
It's not time to square both sides yet (and you only squared the left side anyway).

Instead, divide both sides by x^2 so you get just the square root on the righthand side (RHS). Then it will be time to square both sides of the equation and continue doing the algebra to isolate g.
 
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  • #3
I don't know how the ## x^2 ## got in there=usually this equation reads ## T=2 \pi \sqrt{\frac{l}{g}} ##, but assuming the ## x^2 ## belongs there, it becomes an ## x^4 ## when you square both sides. ## \\ ## To solve for ## g ## , one helpful hint is you can multiply both sides of the equation by ## g ## . The ## g's ## will cancel on the right side, and it will be in the numerator on the left side.
 
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  • #4
berkeman said:
It's not time to square both sides yet (and you only squared the left side anyway).

Instead, divide both sides by x^2 so you get just the square root on the righthand side (RHS). Then it will be time to square both sides of the equation and continue doing the algebra to isolate g.

So my first step of dividing both sides by 2π to give

T/2π = √l/g x^2

is correct?
 
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  • #5
Charles Link said:
I don't know how the ## x^2 ## got in there=usually this equation reads ## T=2 \pi \sqrt{\frac{l}{g}} ##, but assuming the ## x^2 ## belongs there, it becomes an ## x^4 ## when you square both sides. ## \\ ## To solve for ## g ## , one helpful hint is you can multiply both sides of the equation by ## g ## . The ## g's ## will cancel on the right side, and it will be in the numerator on the left side.

Yeah I found that equation without the x^2 asked on here previously, but for some reason the question we've been given includes the additional x^2
 
  • #6
Sorry to message again, but I've got:

g = (4π2Lx4)/T2

Is that correct or am I way off?
 
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  • #8
Charles Link said:
@Alexander8 It's correct.
Ahhh panic over. Thank you very much for the help!
 
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1. How do I rearrange a formula?

To rearrange a formula, you need to use algebraic principles and operations to isolate the variable you want to solve for. This may involve using inverse operations, combining like terms, and applying the distributive property.

2. What is the purpose of rearranging a formula?

Rearranging a formula allows you to solve for a specific variable, making it easier to find solutions to problems and manipulate equations to fit a certain form. It is also useful in simplifying equations and making them more manageable to work with.

3. Can I rearrange any formula?

Yes, as long as the formula contains at least one variable and follows the rules of algebra, it can be rearranged. However, some formulas may be more complex and require more steps to rearrange.

4. What are some common mistakes to avoid when rearranging formulas?

Some common mistakes include forgetting to apply the same operation to both sides of the equation, not distributing terms correctly, and not combining like terms. It is important to double-check your work and make sure all steps are accurate.

5. Is there a specific order to follow when rearranging formulas?

While there is no specific order, it is generally helpful to start by simplifying the equation as much as possible, then isolating the variable you want to solve for, and finally solving for that variable. However, different formulas may require different approaches, so it is important to be flexible and use algebraic principles appropriately.

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