Change in Internal Energy

[Devon 1L]

A gas sample in a cylinder is supplied with 524 kJ of energy as heat. At the same time, a piston compresses the gas, doing 340 kJ of work. What is the change in internal energy of the gas during this process?

[Dorin Coffler 1J]

The gas sample in the cylinder is supplied with 524 kJ of energy, so this is added energy. A piston compressing the gas is also added energy to the system. Therefore you must add both the energy changes given, resulting with an internal energy change of 864 kJ.

[005384106]

will we ever need to do any conversions for units? do these problems always need to be in kJ?

[vanessas0123]

Because q and w are both in kilojoules, you don't need to do anything with the units!

[Luc Zelissen 1K]

will we ever need to do any conversions for units? do these problems always need to be in kJ?

I assume that you will need to do unit conversions on the test to get the answer right. Its always easier to use the units that are in the questions.