R C Sethi Solutions for Chapter: Sound, Exercise 5: EVALUATE YOUR UNDERSTANDING

Differentiate between the following:

Music and noise

A sonar signal sent down from a ship, is reflected from the ocean floor and detected by a hydrophone $0.6$ s later. Calculate the depth of the ocean. Take the speed of sound in sea water as $1500 \mathrm{m} {\mathrm{s}}^{-1}$.

A ship on the surface of water sends a signal and receives it back after $4 \mathrm{s}$ from a submarine inside the water. Calculate the distance of the submarine from the ship. The speed of sound in water is $1450 \mathrm{m} {\mathrm{s}}^{-1}$.

Rohit called up to talk to Reena but her brother Vicky received the call. When Vicky said 'Hello', Rohit immediately recognised his voice without any introduction that it is not Reena on the other side. How did Rohit recognise the voice without seeing the person?

Why is it mandatory for musicians to wear ear protectors during a concert?

Which sound travels faster-the roaring of a lion or the buzzing of a mosquito? Justify your answer.

The diagram given below shows two waves $A$ and $B$. On the basis of the diagram, answer the questions that follows.

With reference to the above diagram, how is the pitch of a note related to the frequency of the sound?

The diagram given below shows two waves $A$ and $B$. On the basis of the diagram, answer the questions that follows.

Which wave from $A$ and $B$, has higher pitch?