Question

An aluminium rod having a length 100 cm is clamped at its middle point

Answer 1

Speed of sound in aluminium will be:

V=√Y/density= √7.8e10/2600= 5480 m/s

Since the rod is clamped at the middle, the middle point is a pressure antinode. The free ends of the rods are the nodes. As the rod vibrates in its fundamental mode, there are no other nodes and antinodes. The length of the rod, which also the distance between the successive nodes, is, therefore, equal to half the wavelength. So, the wavelength of sound in the aluminium rod is:

λ = 2 x length = 200 cm = 2m  

Thus, the frequency of the sound produced which is also equal to the frequency of vibration of the rod is

П= v/ λ= 5480/2= 2740 Hz

Answer 2

here is your answer :)