Q. A pipe open only at one end has a fundamental frequency of 282Hz. A second pipe, initially identical to first pipe, is shortened by cutting off a portion of the open end. At the present, when both pipes vibrate at their fundamental frequencies, a beat frequency of 15 Hz is heard. How various centimetres were cut off the end of the second pipe? The speed of sound is 343 m/s.

Q. Two containers are at same temperature. The first contains gas with pressure p1, molecular mass m1, and root-mean-square speed vrms1. The second contains gas with pressure p2, molecular mass m2, and average speed vavg2. Find out the mass ratio m1/m2 in terms of the variables given.