A transverse harmonic wave is propagating along a taut string. Tension in the string is $50 \mathrm{N}$ and its linear mass density is $0.02 \mathrm{kg}{ \mathrm{m}}^{-1}$. The string is driven by a $80 \mathrm{Hz}$ oscillator tied to one end oscillating with an amplitude of $2 \mathrm{mm}$. The other end of the string is terminated so that all the wave energy is absorbed and there is no reflection. Calculate the average energy of the wave on a $1.0 \mathrm{m}$ long segment of the string.

Which parts of the curve in the figure shown represent compression and rarefaction for a longitudinal wave?

A narrow sound pulse (for example, a short pip by a whistle) is sent across a medium. If the pulse rate is $1$ after every $20s$ (that is the whistle is blown for a split of second after every $20s$)is the frequency of the note produced by the whistle equal to $\frac{1}{20}$ or $0.05Hz$ ?

Waves are generated on a water surface. Calculate the phase difference between two points $A$ and $B$, when, $A$ and $B$ lie on the same wavefront at a distance of $2\lambda$ between them,