Question

A system uses 49 J of energy to do work, and the change in internal energy is 58 J. How much heat was added to the system?

9 J

97 J

107 J

117 J

Answer 1

The answer would be 107J

Answer 2

Answer:- 107 J

Solution:- The work done by the system is given as 49 J and the internal energy change is 58 J. It asks to calculate the heat added to the system.

It is based on first law of thermodynamics and the equation used is:

`\Delta E=q+w`

where w is the work done by the system or on the system. q is the heat energy added to the system or released by the system and
`\Delta E` is the internal energy change.

Since the work is done by the system, the sign of w is negative.

So, w = -49 J

`\Delta E` = 58 J

q = ?

Let's plug in the values in the equation:

58 J = q - 49 J

on rearranging this:

q = 58 J + 49 J

q = 107 J

Hence, 107 J of heat is added to the system. Option three is correct.