Subject Experts Solutions for Chapter: Sound, Exercise 1: PRACTICE QUESTIONS (CLASSROOM WING)

Ratan saw a flash of lightning and after sometime heard the sound of thunder. If the time gap between seeing and hearing is $3 \mathrm{s}$, then write the following steps in sequence to find the height from the ground where the lightning is produced.

(A) Consider the velocity of sound as $330 \mathrm{m} {\mathrm{s}}^{-1}$
(B) Note the time gap ($t$) between seeing and hearing.
(C) From the formula  $speed=\frac{dis\tan ce}{time taken}$, height at which lightning was produced $=$ speed of sound $\times$ time interval.
(D) Substitute the values in the equation ($1$) and find the value of the height of the lightning from the ground.

Write the following steps in sequence to prove that sound travels through liquids.
(A) Place the ear against the side of the container and repeat the activity of hitting one coin with the other inside the water.
(B) Take a metallic container and fill it with water.
(C) Place two coins inside the water. Hit one on the other and observe the sound produced.
(D) Now, a clear and louder sound is heard proving that sound also travels through liquids.

Loudness of sound ____ with _____ in distance.

Which of the following is/are example(s) of stringed instruments?

If more energy is spent to set a body into vibration, then

Jal tarang is an example of

The instruments made of long and hollow pipes with a certain number of holes on the sides are

Noise pollution results in