Response:
0.9 cm
Clarification:
The following illustrates the calculation of the combined rod's length increase:
As established
Length increase = expansion of aluminum rod + expansion of steel rod

= 0.9 cm
We simply summed the expansions of both the aluminum and steel rods to determine the overall increase in the joined rod's length, which must be factored in
Answer:
I'm uncertain
Explanation:
since I didn't provide a correct answer, continue with my inquiries and you can use 'I'm uncertain' for 100 points.
I do not agree. Many materials may fluoresce when exposed to ULTRAVIOLET light, not in microwaves.:)
For this issue, the answer is clarified as the system takes in energy (+). The surroundings contribute 84 KJ of work. Whenever a system is receiving work from its surroundings, the value will be positive. Therefore, it sums to 12.4 KJ + 4.2 = 16.6 KJ.