Final answer:
When the DC offset is reduced from 8 V to 5 V, the 6 V peak sine wave will have its negative peak at -1 V.
Step-by-step explanation:
To address the question on how far negative the sine wave will go when a 6 V peak sine wave that was originally riding on an 8 V DC voltage is now superimposed on a 5 V DC voltage, we must look at the amplitude and displacement properties of sine waves in relation to DC offset.
Initially, the peak of the sine wave is at 6 V above the DC offset, reaching 14 V total (6 V + 8 V). The bottom peak of the sine wave would then be 6 V below the DC offset, at 2 V total (8 V - 6 V). When the DC offset is lowered to 5 V, the top peak will now be 11 V (5 V + 6 V), and the new bottom peak will be -1 V (5 V - 6 V). This means that the sine wave will go 1 V negative.