Equation of a plane progressive wave is given by $y = 0.6\, \sin 2\pi \left( {t - \frac{x}{2}} \right)$.On reflection from a denser medium its amplitude becomes $2/3$ of the amplitude of the  incident wave. The equation of the reflected wave is :-

A source of sound is travelling with a velocity of $40\,km/hour$ towards an observer and emits sound of frequency $2000\,Hz$ . If the velocity of sound is $1220\,km/hour$ , what is the apparent frequency heard by the observer ..... $Hz$

Two waves represented by ${y_1} = a\sin \frac{{2\pi}}{\lambda }\left( {vt - x} \right)$ and ${y_2} = a\cos \frac{{2\pi }}{\lambda }\left( {vt - x} \right)$ are superposed. The resultant wave has an amplitude equal to

Calculate the temperature at which the speed of sound will be two times its   ..... $K$ value at $0\,^oC$

A string with a mass density of $4\times10^{-3}\, kg/m$ is under tension of $360\, N$ and is fixed at both ends. One of its resonance frequencies is $375\, Hz$. The next higher resonance frequency is $450\, Hz$. The mass of the string is

Speed of sound waves in a fluid depends upon