No, although there are several theories with increasing evidence, there is still no way to know for sure how it occurred. The great mystery of the beginning of universe is way too vast and vague. Theories can only be proven by presenting a solid proof, but great creations such as universe itself doesn't have to be solved. Various possibilities must have happened or there must be a one conclusion leading to its existence; but moreover, it is not our problem to solve. The confirmation of beginning of its existence will only feed the curiosity of humans.
Answer:
yes it is a useful mechanism
Answer: 0.04metres
Explanation:
The wavelength of a wave is the distance covered by the wave after one complete cycle. It is measured in metres, and represented by the symbol λ
Recall that Velocity (V) = Frequency F x wavelength λ
V = F λ
Make λ the subject formula
λ = V / F
In this case Frequency = 0.4 kHz
Convert kilohertz to hertz by multiplying 0.4 by 1000 i.e (0.4 x 1000Hz) = 400Hz
Velocity of wave = 16 m/s
So, λ = V / F
λ = 16 m/s / 400Hz
λ = 0.04metres
Thus, the wavelength of a wave is 0.04metres
C. The nervous system sends signals to make muscles move.
A,B,C,D I'm pretty sure, but check with others who answer the question too.