Hydrogen gas is harmless to your feet so since you don’t need protection against it that seems the best answer.
we only see wavelengths from 400–700 nanometers.
Well, you would reply that that's not what theories are. Theories explain the how and the why, laws explain the what. So, the Big Bang theory isn't "just a theory". It's a theory, it explains the how. (Also, if someone tells you it's anti-God or whatever, tell them the thoery was created by a Catholic scientist. True fact.) I hoped this helped!!! (You don't have the include who created the theory if this is for homework.)
His role as a field research is that of a: Complete participant!
(Option D.)
~Good luck!
Answer:
|Δf| = 37.3 kHz
Explanation:
given,
peak velocity = 4 m/s
speed of the sound = 1500 m/s
frequency = 7 MHz




= 37.3 kHz
|Δf| = 37.3 kHz
hence, frequency shift between the opening and closing valve is 37.3 kHz