The speed of sound is $310 \, m s^{-1}$. $A$ person fires a gun and the echo is heard after $1.5 \, s$. Calculate the distance of the person from the cliff from which the echo takes place. (in $, m$)

$A$ ship sends out ultrasound waves that are detected after $4 \, s$ upon reflection from the seabed. If the speed of ultrasound through seawater is $1550 \, m \, s^{-1}$,find the distance of the seabed from the ship. (in $, m$)

State two practical uses or applications of echoes.

How do you account for the fact that two strings can be used to give notes of the same pitch and loudness but of different quality?

Explain with the help of a diagram,how defects in a metal block can be detected using ultrasound.

Two friends were playing on identical guitars whose strings were adjusted to give notes of the same pitch. Will the quality of the two notes be the same? Give a reason for your answer.