Question Regarding Thermal Energy

[dismalice]

Homework Statement

An ideal gas is at 20C. The gas is cooled, reducing the thermal energy by 35%, What is the new temperature in C?

Homework Equations

None in particular.

The Attempt at a Solution

35% of 20C is 7, 20-7= 13C

 

[Hootenanny]

Homework Statement

An ideal gas is at 20C. The gas is cooled, reducing the thermal energy by 35%, What is the new temperature in C?

Homework Equations

None in particular.

The Attempt at a Solution

35% of 20C is 7, 20-7= 13C

Note the phrase that I have highlighted in red above.

 

[dismalice]

Note the phrase that I have highlighted in red above.

I do not follow, can you please explain to me what you mean?

 

[Hootenanny]

I do not follow, can you please explain to me what you mean?

Sorry for being so cryptic. I misread your post - I thought that you were saying the answer was 7, which obviously it isn't! Your answer is correct.

 

[dismalice]

Sorry for being so cryptic. I misread your post - I thought that you were saying the answer was 7, which obviously it isn't! Your answer is correct.

Mastering Physics is not taking that answer as correct. Is there another way of looking at this problem?

 

[dismalice]

Can anyone else assist me with this problem?

 

[Hootenanny]

Can anyone else assist me with this problem?

The internal energy of an ideal gas is directly proportional to the temperature. Therefore, a 35% reduction in internal energy will result in a 35% reduction temperature. Unless there is more information that you have provided us with, that is the answer.

Computerised marking software can be notoriously pedantic. Are you sure that you are entering the answer in the correct form? I.e. with/without units, to the correct number of significant figures?

 

[dismalice]

The internal energy of an ideal gas is directly proportional to the temperature. Therefore, a 35% reduction in internal energy will result in a 35% reduction temperature. Unless there is more information that you have provided us with, that is the answer.

Computerised marking software can be notoriously pedantic. Are you sure that you are entering the answer in the correct form? I.e. with/without units, to the correct number of significant figures?

Yes, I am 100% sure, I have even tried spelling out Celsius and it refuses to take the response.

 

[Mapes]

A gas still has internal energy at 0, -10, even -100°C. You need to work with an absolute temperature scale. Know what I mean?