Tag: physics

The volume of a cinema theatre is 100m x 60m x 20m and total acoustic absorption in it is 6800metric sabine. The reverberation time in that theatre is

In theatres, big halls., the reverberation of sound is a common problem.

A meeting hall of volume $100\times30\times10 m^3$ has a reverberation time of 3 seconds. If 1000 visitors are in the hall. The absorption of total visitors if the sound absorption of each visitor is 0.5 is:

A source of sound A emitting waves of frequency 1800 Hz is falling towards ground with a terminal speed v. The observer B on the ground directly beneath the source receives wave of frequency 2150hz. The source A receives waves, reflected from frequency nearly: (Speed of sound = 343 m/s)

A man standing between two parallel hills, claps his hand and hears successive echoes at regular intervals of $1\ s$. If velocity of sound is $340 \mathrm { ms } ^ { - 1 }$, then the distance between the hill is

The time of reverberation of a room A is one second. What will be the time (in seconds) of reverberation of a room, having all the dimensions double of those of room A:

Standing waves and echoes are based on which acoustic phenomenon?

The reverberation time of a theatre is $0.1 sec$. The volume of the other theatre is exactly half. If the total absorption is same then the reverberation time of second one

When a source of sound crosses an obsever then change in appearent frequency obseved by the  observer is $2$% of its initial frequency. If the speed of sound is $350 m/s$ then be-

An auditorium of dimensions $(100\times40\times10)\space m^3$ contains $1000\space m^2$ curtains of absorption coefficient $0.2\space m^{-2},\space 2000 m^2$ of carpets of absorption coefficient $0.7\space m^{-2}$. If $1000$ men of absorption coefficients $0.9$ per person are sitting in the hall, then reverberation time is