What is reverberation?

$A$ body vibrating with a time period of $5 \times 10^{-3} \text{ s}$ produces a wave travelling in a medium with a velocity of $1450 \text{ m s}^{-1}$. Calculate its wavelength and the frequency of vibration of the body.

What are elastic waves? Name two kinds of elastic waves.

Write true or false for the following statement: The distance between a crest and the next trough in a wave motion is $\lambda / 4$.

$(i)$ Even if a loud explosion were to take place at any place on the moon,it would not be heard at a nearby point. Give reason.
$(ii)$ Explain in brief the dependence of speed of sound on the nature of the material medium and temperature.
$(iii)$ Identify the two factors on which the loudness of sound depends.

Write true or false for the following statement: Sound produced by a sounding body of frequency $300 \text{ Hz}$ covers $34 \text{ m}$ in the time the sounding body produces $30$ vibrations.