$A$ sound wave of frequency $160 \,Hz$ has a velocity of $320 \,m/s$. When it travels through air, the particles having a phase difference of $90^{\circ}$ are separated by a distance of: (in $cm$)

$A$ source $S$ of frequency $f_0$ and an observer $O$,moving with speeds $v_1$ and $v_2$ respectively,are moving away from each other. When they are separated by a distance $a$ at $t = 0$,a pulse is emitted by the source. This pulse is received by $O$ at time $t_1$. Then $t_1$ is equal to:

An ultrasonic signal sent from $SONAR$ returns to it after reflection from a rock after a lapse of $1 \, s$. If the velocity of ultrasound in water is $1600 \, m/s$,the depth of the rock in water is ..... $m$.

The enclosed air inside a closed box of rigid walls has pressure $P_1$. The density of air inside this box is constant. On heating the gas, the pressure of the enclosed air is increased from $P_1$ to $P_2$. Now it is observed that the sound travels $1.4$ times faster than at pressure $P_1$. The ratio $P_2/P_1$ is:

Newton assumed that sound propagation in a gas takes place under which condition?

When pressure on a gaseous medium is changed at constant temperature,what will be the effect on the speed of sound wave in it?