Final answer:
The change in internal energy of the system is -50 J, indicating a decrease, according to the first law of thermodynamics.
Step-by-step explanation:
The question involves internal energy change in a thermodynamic system, which is a concept in Physics. According to the first law of thermodynamics, the change in internal energy (ΔU) of a system is equal to the heat (Q) added to the system minus the work (W) done by the system. Therefore, when a system does 200 J of work and absorbs 150 J of heat, the change in internal energy can be calculated as:
ΔU = Q - W = 150 J - 200 J = -50 J
The negative sign indicates that the internal energy of the system has decreased by 50 J.