Question

What is the change in internal energy if 30 J of thermal energy is released from a system, and the system does 40 J of work on the surroundings? Use U = Q - W. A. 70 J B. 10 J C. -10 J D. -70 J

Answer 1

Answer:

The correct answer to the following question will be Option C (-10 J).

Explanation:

The given values are:

Work done by the system, W = 40 J

Thermal energy, Q = 30 J

Change in internal energy, U = ?

As we know,

⇒  $U=Q-W$

On putting the values in the above expression, we get

⇒  $U=30-40$

⇒      $=-10 \ J$

So that the change in internal energy will be "-10 J".