Energy can not be created or destroyed but can change from one form to another.
example: as a roller coaster cart loses height the more speed it gains, the potential energy is transferred into kenetic energy
Compressions are the areas of high pressure while rarefractions are low pressure area
Answer:
Option C
Explanation:
Kinetic energy is the energy that the body possesses by virtue of its motion.
The formula for Kinetic energy is given by 
Using this formula let us find kinetic energy for the bodies given and find out which is the greatest
A) KE = 
B) KE =
C) KE = 
D) KE = 
Comparing these we find that 9mv^2 is the highest.
Hence option C is the answer.