HARD
9th CBSE
IMPORTANT
Earn 100

With the help of a labelled diagram, explain the working of the human ear.

Important Questions on Sound

HARD
9th CBSE
IMPORTANT
Illustrate with the help of an experiment that sound requires a medium to propagate.
MEDIUM
9th CBSE
IMPORTANT

A sound wave of length 70 cm travels 840 m in 25 seconds. What is the velocity and frequency of sound?

Note: This question given in the book seems to have error and the modified question should be as given below.

A sound wave of length 70 cm travels 840 m in 2.5 seconds. What is the velocity and frequency of sound?
HARD
9th CBSE
IMPORTANT
An echo is heard after 0.8 seconds, when a person fires a cracker 132.8 m from a high building. Calculate the speed of sound.
HARD
9th CBSE
IMPORTANT
A source of wave produces, 40 crests, and 40 troughs in 0.4 seconds. Find the frequency of the wave.
MEDIUM
9th CBSE
IMPORTANT
Why an echo is not heard when distance between source of sound and reflecting body is 10 m ?
MEDIUM
9th CBSE
IMPORTANT
The distance between the crest and trough of a transverse wave is 15 cm, what is the velocity of the wave if its frequency is 1000 Hz ?
MEDIUM
9th CBSE
IMPORTANT
Two astronauts cannot hear each other on the moon. Why ?
HARD
9th CBSE
IMPORTANT
Sometimes our dog begins to bark without any reason. Can you explain, Why ?