You can picture a sound wave a lot like a Slinky wave . . . a
thicker, compressed blob moving along the path, with thinner,
stretched-out places before and after it.
The thicker parts of a sound wave, where the air is more dense,
are called compressions.
The thinner parts of a sound wave, where the air is less dense,
are called rarefactions.
The correct answer would be A
Answer: 
The ball was thrown at the speed of 
.
Maximum height achieved is 
Time of flight is t.
Now, the time the ball takes to achieve maximum height = the time taken by ball to fall back = 
let us just consider the second half of the flight. At , the velocity would be zero. let us consider as the initial velocity for the second half of the flight i.e. 
Using the equation of motion:
where, 
is the final velocity, a is the acceleration, t is the time taken.
Because the ball would fall under gravity, hence a=g and time of flight would be t/2
Radio waves have the lowest frequency, but 0 hz is the lowest
