Final answer:
The frequency of the wave represented by the equation Y = 0.39 sin(20πt + π/2) is 10 Hz, obtained by dividing the angular frequency 20π radians per second by 2π.
Step-by-step explanation:
The equation given for a plane progressive wave is Y = 0.39 sin(20πt + π/2). To find the frequency of the wave, we need to identify the angular frequency from the equation. The angular frequency (ω) is the coefficient of t in the equation, which is 20π radians per second. The frequency (f) is related to the angular frequency by the formula ω = 2πf. Therefore, we can calculate the frequency of the wave as follows:
f = ω / (2π) = 20π / (2π) = 10 Hz.