Finding milk mass from final temperature of milk and coffee

[chops369]

Homework Statement

How much milk at 11 degrees celsius was added to 0.16 kg of coffee at 91 degrees celsius if the final temperature is 76.8 degrees celsius?

Homework Equations

Well my teacher explained how to rearrange cm∆T = cm∆T to somehow come up with an equation to solve for the final temperature: Tf = T₁ * m₁ + T₂ * m₂ / (m₁ + m₂) How would I rearrange that to solve for one of the masses?

The Attempt at a Solution

No idea :(

 

[LowlyPion]

Homework Statement

How much milk at 11 degrees celsius was added to 0.16 kg of coffee at 91 degrees celsius if the final temperature is 76.8 degrees celsius?

Homework Equations

Well my teacher explained how to rearrange cm∆T = cm∆T to somehow come up with an equation to solve for the final temperature: Tf = T₁ * m₁ + T₂ * m₂ / (m₁ + m₂) How would I rearrange that to solve for one of the masses?

The Attempt at a Solution

No idea :(

I think you are missing a parentheses.

Tf = (T₁ * m₁ + T₂ * m₂) / (m₁ + m₂)

You want to consider the rather aptly named weighted average to determine your answer. Remember though that temperatures need to be in Kelvin.

As to solving for a mass, it's your only unknown. Think Nike: Just do it.

 

[chops369]

I'm not too sure I catch your drift.

 

[LowlyPion]

I'm not too sure I catch your drift.

Just plug in the numbers and solve.