The intensity of a sound wave is defined as the amount of energy passing through a unit area of the wave front in unit of time.
Answer: Wavelength is the measure of the length of a complete wave cycle. The velocity of a wave is the distance traveled by a point on the wave. In general, for any wave the relation between Velocity and Wavelength is proportionate. It is expressed through the wave velocity formula.
Explanation: For any given wave, the product of wavelength and frequency gives the velocity. It is mathematically given by wave velocity formula written as-
V=f×λ
Where,
V is the velocity of the wave measure using m/s.
f is the frequency of the wave measured using Hz.
λ is the wavelength of the wave measured using m. Velocity and Wavelength Relation
Amplitude, Frequency, wavelength, and velocity are the characteristic of a wave. For a constant frequency, the wavelength is directly proportional to velocity.
Given by:
V∝λ
Example:
For a constant frequency, If the wavelength is doubled. The velocity of the wave will also double.
For a constant frequency, If the wavelength is made four times. The velocity of the wave will also be increased by four times.
Hope you understood the relation between wavelength and velocity of a wave. I truely hope this helps you out tho! Goodluck!
Answer:
if im not mistaken i think its d let me know if correct plz
Answer:Racquet force is twice of Player force
Explanation:
Given
ball arrives at a speed of 
ball returned with speed of 
average Force imparted by racquet on the ball is given by

where 
time of contact of ball with racquet


When it land on the player hand its final velocity becomes zero and time of contact is same as of racquet


From 1 and 2 we get

Hence the magnitude of Force by racquet is twice the Force by player
What gas? Gas is an invisible form so I don't see how it would have a "defined structure".