Nah gaya seperti titik fashion seperti apa yang Anda mana dan hal-hal seperti itu. (tell me if you cant understand)
Before answering the question, first we have to understand a longitudinal wave.
A longitudinal wave is a type of mechanical wave in which the direction of wave propagation is parallel to the particle vibration of the medium.
In this type of wave, there will be compressions and rarefactions. Compressions are the high pressure regions where the particles of the medium are very close to each other. The rarefactions are the low pressure regions of a longitudinal wave where the particles are not so close to each other.
Hence, a longitudinal wave is a series of compressions and rarefactions.
The wavelength of a longitudinal wave is defined as the distance between two successive compressions or rarefactions.
Hence, the correct answer to the question is C) by measuring the distance between adjacent rarefactions.
Answer:
The rate of flow of water is 71.28 kg/s
Solution:
As per the question:
Diameter, d = 18.0 cm
Diameter, d' = 9.0 cm
Pressure in larger pipe, P = 
Pressure in the smaller pipe, P' = 
Now,
To calculate the rate of flow of water:
We know that:
Av = A'v'
where
A = Cross sectional area of larger pipe
A' = Cross sectional area of larger pipe
v = velocity of water in larger pipe
v' = velocity of water in larger pipe
Thus

v' = 4v
Now,
By using Bernoulli's eqn:

where
h = h'




Now, the rate of flow is given by:


20 kg*m/s because there is 2 kg mass and 10 m/s so you can multiply.