522 J of work are done on a system in a process that decreases the system's thermal energy by 240 J. How much heat energy is transferred to or from the system?

ΔQ = - 762 J (Negative Sign shows heat transfer from the system)

Explanation:

The heat transferred to or from the system can be given by using First law of Thermodynamics as follows:

where,

ΔQ = Heat Transferred to or from system = ?

ΔU = Change in Internal Energy of System = Change in Thermal Energy

ΔU = - 240 J (negative sign due to decrease in energy)

W = Work done on system = -522 J (negative sign due to work done "on" system)

Therefore,

ΔQ = - 762 J (Negative Sign shows heat transfer from the system)