Question

A small, closed chamber of gas is heated. When the gas in the chamber expands,it does 5 J of work on a piston. The gas has an initial energy of 8J and a finalenergy of 30 J. Considering the equation for the firsI law of thermodynamics (AU=Q+W), does the work done in this scenario have a positive or negative value?

Answer 1

Given:

Work done, W = 5 J

Initial energy = 8J

Final energy = 30J

Let's determine if the work done have a positive or nrgative value.

Appy the equation for the first lae of thermodynamics:

$\Delta U=Q-W$

Where:

U is the change in internal energy

Q is the added heat

W is the work done

To find the work done here, we have:

Rewrite the formula for W

$W=Q-\Delta U$

Where:

ΔU = 30J - 8J = 22J

Q = 5J

Thus, we have:

$\begin{gathered} W=5J-22J \\ \\ W=-17J \end{gathered}$

Therefore, the work done here is -17J.

This means the work done in this scenario has a negative value.

ANSWER:

The work done in this scenario has a negative value