A man standing in front of a vertical cliff fires a gun. He hears the echo after $3$ seconds. On moving closer to the cliff by $82.5 \mathrm{m}$, he fires again. This time, he hears the echo after $2.5$ seconds. Calculate the distance of the cliff from the initial position of man.

A man standing in front of a vertical cliff fires a gun. He hears the echo after $3$ seconds on moving closer to the cliff by $82.5 \mathrm{m}$, he fires again. This time, he hears the echo after $2.5$ seconds. Calculate the velocity of sound.

The wavelength and frequency of a sound wave in a certain medium is $25 \mathrm{cm}$ and $1750 \mathrm{Hz}$ respectively. Calculate the velocity of sound.

The wavelength and frequency of a sound wave in a certain medium is $25 \mathrm{cm}$ and $1750 \mathrm{Hz}$ respectively. Keeping the medium same, calculate the new frequency, if the wavelength is changed to $18 \mathrm{cm}$.

A $10$ ohm thick wire is stretched so that its length becomes three times. Calculate resistance of the new wire.

Why do coastal regions have temperate climate?

Why drinks are cooled better by ice than ice cold water?

Define specific latent heat of ice. Give its SI units. Calculate the mass of ice required to lower the temperature of $300 \mathrm{g}$ at ${40}^{°}\mathrm{C}$ to water at $0^{°}\mathrm{C}$. (specific latent heat of ice $=336 {\mathrm{Jg}}^{-1}{\mathrm{K}}^{-1}$, (specific heat of water$=4.2 {\mathrm{Jg}}^{-1}{\mathrm{K}}^{-1}$).