Help rearranging a formula to solve for different variables

[Noah159]

Homework Statement

[/B]
I just got this formula from class : Q=mc(T2-T1) and got task to make 2 more formulas from this one

Homework Equations

How do I make these formulas : T1=? and T2=?

The Attempt at a Solution

T2=Q:mc-T1
T1=-T1
T1=Q:mc+T2
Thanks for help

 

[berkeman]

Homework Statement

[/B]
I just got this formula from class : Q=mc(T2-T1) and got task to make 2 more formulas from this one

Homework Equations

How do I make these formulas : T1=? and T2=?

The Attempt at a Solution

T2=Q:mc-T1
T1=-T1
T1=Q:mc+T2
Thanks for help

Welcome to the PF.

The equations look okay (see kuruman's post below) except for the bolded part. What do you mean by that equation?

 

[gneill]

Note that I changed the thread title to: "Help rearranging a formula to solve for different variables".

I think this will make it a bit more clear what the thread is about.

 

[kuruman]

T2=Q:mc-T1

This equation is also problematic. Starting with your equation Q=mc(T2-T1), it looks like you first divided both sides by mc. That is good. What expression did you get? And once you got that expression, what did you do to it to get T2=Q:mc-T1 ?

 

[Noah159]

I got Delta T=Q:mc

Delta T=T2-T1 so formula is T2-T1=Q:mc and I just used simple math trick that if you change sides, it just changes from + to - and - to + e.g x=+4 meaning x-4=0

So from T2-T1=Q:mc formula I got these two:
T1=Q:mc-T2
T2=Q:mc+T1

 

[kuruman]

You got the equation for T2 correct this time, but the equation for T1 is incorrect. Starting with T2-T1=Q:mc what do you get, using your simple math trick, when you move T1 to the left side and Q:mc to the right side?

 

[Noah159]

T2-T1=Q:mc
T2=Q:mc+T1
T2:Q*mc=T1
T1=T2:Q*mc
Did I get it right this time?

 

[kuruman]

Sorry, no.

T2=Q:mc+T1 is correct. You want to have Q:mc on the other side. What does your simple math trick say you should do to achieve this goal? You said it yourself

it just changes from + to - and - to +

So ...

 

[Noah159]

T2-T1=Q:mc

I can't just move Q:mc freely becouse of division between Q and mc and because of multiplication between m and c.
E.g ρ=m:V
Makes m=ρV
So I can't use my math trick
Sorry if I got your question wrong

 

[kuruman]

I can't just move Q:mc freely becouse of division between Q and mc and because of multiplication between m and c.

Yes you can. Here is how and why. Let w = Q:mc. Then your equation becomes T2-T1 = w. Now move things around to get T1 alone on one side. Finally, replace w with what it is the same as, namely Q:mc. This is how algebra works!

 

[Noah159]

+T2-T1=+w
+T2=+T1+w
+T2-w=+T1
T2-Q:mc=T1
I hope i got it right this time, did I?

 

[kuruman]

You did, and I hope you learned something from this experience.

 

[Noah159]

Thanks for your help. I definitely learned a lot.