A string of mass $2.5\ kg$ is under a tension of $200\ N$ . The length of the stretched string is $20.0\ m$ . If the transverse jerk is struck at one end of the string, the disturbance will reach the other end in .... $\sec$

A point source emits sound equally in all directions in a non-absorbing medium. Two points $P$ and $Q$are at distances of $2m$ and $3m$ respectively from the source. The ratio of the intensities of the waves at $P$ and $Q$ is

The length of an open organ pipe is $0.5\, m$. Calculate the fundamental frequency of the pipe, if the velocity of sound in air be $350\, m/sec$   .... $Hz$

Four sources of sound each of sound level $10\,dB$ are sounded together, there sultant intensity level will be ... $dB$

A whistle revolves in a circle with an angular speed of $20\, rad/s$ using a string of length $50\, cm$. If the frequency of sound from the whistle is $385\, Hz$, then what is the minimum frequency heard by an observer, which is far away from the centre in the same plane  ..... $Hz$ (speed of sound is $340\, m/s$)

A $10\, m$ long steel wire has mass $5\,g$. If the wire is under a tension of $80\, N$, the speed of transverse waves on the wire is   .... $ms^{-1}$