A cavity that has a hole in it......it's the best example of black body radiators....
B. The number of coils of wire around the core
Answer:
we have formula of frequency :
frequency(f)= speed of sound(c)/wavelength(λ)
for wavelength we swipe it with frequency as follows
λ=c/f
λ=300,000,000/101,700,000
λ=2.949
Answer:

Explanation:
= Avogadro's number = 
e = Charge of electron = 
k = Coulomb constant = 
Z = Atomic number of water = 18
M = Molar mass of water = 0.018 kg/mol
m = Mass of person
The charge is given by

Total number of protons and electrons in each sphere




Electrical force is given by

The electrostatic force of attraction between them is 