$A$ string of mass $100 \, g$ is clamped between two rigid supports. $A$ wave of amplitude $2 \, mm$ is generated in the string. If the angular frequency of the wave is $5000 \, rad/s$,then the total energy of the wave in the string is ..... $J$.

$A$ musical instrument $P$ produces sound waves of frequency $n$ and amplitude $A$. Another musical instrument $Q$ produces sound waves of frequency $n/4$. The waves produced by $P$ and $Q$ have equal energies. The amplitude of waves produced by $Q$ will be

The intensity of a sound wave while passing through an elastic medium falls by $10\%$ as it covers $1 \ m$ distance through the medium. If the initial intensity of the sound wave was $100 \ dB$,its value after it has passed through $3 \ m$ thickness of the medium will be .... $dB$.

Statement-$1$: Two longitudinal waves given by equations $y_1(x, t) = 2a \sin(\omega t - kx)$ and $y_2(x, t) = a \sin(2\omega t - 2kx)$ will have equal intensity.
Statement-$2$: Intensity of waves of given frequency in the same medium is proportional to the square of amplitude only.

On getting reflected at a surface,the intensity of sound is found to be decreased by $20 \%$. If $A$ be the amplitude of the incident sound waves,then the amplitude of reflected sound waves is

The amplitude of a wave at a distance $r$ from a point source is $A$. What will be the amplitude at a distance $2r$ from the source?