Question

2016

(d) The speed of a transverse wave on a string is 110 m s¯1 . The tension in the string is 340 N. Calculate the mass per unit length of the string.

(o) A certain radioactive sample has a half-life of 3.83 days and is measured to have an activity of 63 Bq. Calculate how many radioactive atoms are present in the sample at the time of the measurement.

Q2:

(c) A person hums into the top of a well and finds that standing waves are established at frequencies of 28.8, 48.0, and 67.2 Hz. The frequency of 28.8 Hz is not necessarily the fundamental frequency. Determine the depth of the well. [5 marks]

(d) A tube, open at only one end, is cut into two shorter (non-equal) lengths. The piece open at both ends has a fundamental frequency of 436 Hz, while the piece open only at one end has a fundamental frequency of 910 Hz. Calculate the fundamental frequency of the original tube. [5 marks]

Answer 1

Shing v=tlomis mass per unit langth tio