Rearranging Equation: Make A Subject - Ideas?

[missyfit]

Homework Statement

F = A [Q][1][Q][2] / [r][2]

Rearrange make A subject

any one have any ideas?

Homework Equations

The Attempt at a Solution

 

[tiny-tim]

Welcome to PF!

Hi missyfit! Welcome to PF!

(try using the X² and X₂ tags just above the Reply box )

Do you mean F = A Q₁Q₂ / r² ?

Just move the Qs and the r to the other side…

what do you get? ​

 

[missyfit]

F = A Q1Q2 / r2 ?
yes this is what was meant thanks

by moving the Qs and r to other side is A the subject if it is left on the right?

 

[Redbelly98]

by moving the Qs and r to other side is A the subject if it is left on the right?

Yes.

 

[tiny-tim]

Or you can always swap the sides round, if it makes you happier.

 

[missyfit]

Thanks for both you inputs can you give an example of how you may work this out. do i need to do anything with the sqare root?

missyfit

 

[tiny-tim]

No, you show us what you think, and we'll comment.

 

[missyfit]

first i thought that swaping side over then wasnt sure what i should do with square root

F = A Q1Q 2 / r2
A Q1Q2 / r2 = F
A Q1Q2 / r2 x Q1Q2 / r2 = F Q1Q2 / r2 x Q1Q2 / r2
A = F Q1Q2 / r2

this all seems abit bulky.

 

[tiny-tim]

Hi missyfit!

(just got up :zzz: …)

A Q1Q2 / r2 x Q1Q2 / r2 = F Q1Q2 / r2 x Q1Q2 / r2
A = F Q1Q2 / r2

uhh? whatever are you doing?

start again. ​

 

[missyfit]

I guess i made a mess of this just learning equations and already finding it stressful. Dont worry thanks for help any way was following system we have been given to do equation clearly not very effective.

 

[tiny-tim]

Hi missyfit!

(just got up :zzz: …)

I guess i made a mess of this just learning equations and already finding it stressful. Dont worry thanks for help any way was following system we have been given to do equation clearly not very effective.

Sorry about the stress.

Start by multiplying both sides of the original equation by r² …

what do you get? ​