Answer:
30√2 ≈ 42.426 volts
Step-by-step explanation:
The RMS value of the signal is the DC equivalent. For a sine wave, the mean of the square is half the square of the peak value. Then the Root-Mean-Square is ...
RMS = √((Vp)^2/2) = Vp/√2
For Vp = 60 volts, the equivalent DC voltage is ...
V = (60 volts)/√2 = 30√2 volts ≈ 42.426 volts