Answer:
minimum frequency = 170 Hz
Explanation:
given data
One path long = 20 m
second path long = 21 m
speed of sound = 340 m/s
solution
we get here destructive phase that is path difference of minimum 
here λ is the wavelength of the wave
so path difference will be
21 - 20 =
λ = 2 m
and
velocity that is express as
velocity = frequency × wavelength .............1
frequency = 
minimum frequency = 170 Hz
Answer:
hi what is your question?? say in English please
Answer:
D
Explanation:
because it doesn't agree with the law of definite proportion
and energy can niether be created nor destroyed but can be transformed from one form to another
A. electrons<span> and </span>neutrons<span> B. </span>electrons<span> and </span>protons<span> C. </span>protons<span> and </span>neutrons<span> D. all particles are attracted to each other. According to atomic theory, </span>electrons<span> are usually found: A. in the </span>atomic nucleus<span> B. outside the nucleus, yet very near it because they are attracted to the </span>protons<span>.</span>
