Mechanical waves on the surface of a liquid are

A mass of $20\  kg$ is hanging with support of two strings of same linear mass density. Now pulses are generated in both strings at same time near the joint at mass. Ratio of time, taken by a pulse travel through string $1$ to that taken by pulse on string $2$ is

A uniform rope having some mass hanges vertically from a rigid support. A transverse wave pulse is produced at the lower end. The speed $(v)$ of the wave pulse varies with height $(h)$ from the lower end as:

Mechanical wave (sound wave) in a gas is

A wire of $9.8 \times {10^{ - 3}}kg{m^{ - 1}}$ passes over a frictionless light pulley fixed on the top of a frictionless inclined plane which makes an angle of $30°$ with the horizontal. Masses $m$ and $M$ are tied at the two ends of wire such that $m$ rests on the plane and $M$ hangs freely vertically downwards. The entire system is in equilibrium and a transverse wave propagates along the wire with a velocity of $100 ms^{-1}$. Chose the correct option $m =$ ..... $kg$

Spacing between two successive nodes in a standing wave on a string is $x$ . If frequency of the standing wave is kept unchanged but tension in the string is doubled, then new spacing between successive nodes will  become