[moop1]

Hi,

Sabrina heats up one steel rod of 50 g. When the rod is 85 °C, she puts it in a themor containing 225 g of ethnaol, at a temperature of 20 °C. The temperature of the ethanol goes to 22,6 °C. If we consider that there isnt any loss of energy in the environment, what is the specific heat capacity of steel?
Q=m.c.delta t

= 225 g . 2,46 J/g .°C. (22,6-20) °C
= 1439,1 J

C= Q/(m. delta t)
= -1439,1 J/(50 g * (final temp-85)

My only problem was how can I know the final temperature Finally, when I saw what the solution was, I was kind've disturbed. It says that the finaly temperature of the steel is 22,6... How do they know that ? Why couldn't it be 30, ,40 ,etc. °C ?
Can somebody explain me ? THank you!

*By the way, your verification process for registration was hard -__-. (It's barely readable)

[Arkcon]

I'm guessing the temperature is measured with a thermometer.  You need this information to solve the problem, so they have to provide it.

[moop1]

Well, there's no mention of a thermometer.... Any suggestions ?

[Borek]

Well, there's no mention of a thermometer.... Any suggestions ?

There is no need to mention a method, when the measurement result is given.

Let's say I am 5'8". I have not mentioned the ruler - does it make the information invalid?

Or perhaps your problem is with the wording - it says the final temperature of ethanol, not the final temperature of the ethanol AND the rod? Well, if it is the FINAL temperature, whole system must be at thermal equilibrium, which means all parts have the same temperature.