Answer:
When the sound wave enters the water its wavelength increase.
Explanation:
Given:
Speed of sound in air 
Speed of sound in fresh water 
We know that when wave travel into one medium to another medium frequency doesn't change.
Velocity is given by,

In above equation frequency is constant,
So when sound wave enters the water wavelength increase because speed sound is increase in water as compare to air.
Therefore, when the sound wave enters the water its wavelength increase.
Answer:
Area under a curve can be estimated via block counting, calculated with simple geometry if the velocity has constant accelerations, or calculated by integration if the velocity can be described by a mathematical equations.
The area under a velocity time curve will be the product of velocity and time which equals displacement.
Answer: A.
Explanation:
Since pitch and frequency are the same thing when frequency is higher the wavelength decreases and A is the only valid answer.
Think like this: 10 is twice as much as 5.
Answer A pushes 2 squares east and 4 squares sout, being doubled just as 10 is to 5. Happy to help :)
its because it allows modern astronomers the ability to see farther out and more accuratly