Question

When compressing a gas, a work of 355 J is done on the system and simultaneously the system yields a heat of 85 J. What is the change in internal energy for the system?

Answer 1

Answer;

270Joules

Explanations:

The formula formula for calculating the internal energy for the system is expressed as:

`\triangle U=Q+W`

where;

Q is the heat supplied to the system

W is the workdone by the system

Since this is compression, work is done on the gas. Work done is positive. The term, the system yields heat implies that the system looses heat (heat is negative)

Q = -85J

W = 355J

Substitute

`\begin{gathered} \triangle U=-85\text{ + 355} \\ \triangle U=270Joules \end{gathered}`

Hence the change in internal energy for the system is 270Joules