A system loses 14.2 kJ of heat while performing 7.2kJ of

work on the surroundings. If the initial internal energy, E, is 77.6 kJ, what is the final value of E?

56.2 kJ
70.6 kJ
99.0 kJ
84.6 kJ

What is 77.6-14.2-7.2?

To find the final value of the internal energy (E), we need to consider the first law of thermodynamics, which states that the change in internal energy of a system is equal to the heat added to the system minus the work done by the system on the surroundings.

The equation for the first law of thermodynamics is:
ΔE = Q - W

Given that the system loses 14.2 kJ of heat (Q) and performs 7.2 kJ of work (W) on the surroundings, we can substitute these values into the equation:
ΔE = -14.2 kJ - 7.2 kJ

Calculating the expression gives us:
ΔE = -21.4 kJ

To find the final value of E, we need to subtract the change in internal energy from the initial internal energy:
Final E = Initial E + ΔE
Final E = 77.6 kJ - 21.4 kJ

Calculating the expression gives us:
Final E = 56.2 kJ

Therefore, the final value of E is 56.2 kJ. Therefore, the correct answer is 56.2 kJ.