Shown below is a tuning fork A and B both having frequency 256 hertz. Next to B is
placed a light pith ball hanging from a support and just touching the tuning fork B and
is stationary.
When the tuning fork A is struck with a hammer, it is noticed that soon the pith ball
near B begins to bounces about vigorously as shown in the figure.

i) Name and explain the phenomena that causes the above observation.
ii) After some time, the pith ball stops bouncing. Explain
iii) What would your observations be, if the frequency of the tuning forks were

Asked by saibaba1069 | 26th Feb, 2021, 12:54: AM

Expert Answer:

(1) Both tuning forks will vibrate in same freuency. When tuning fork A is made to vibrate ,
sound wave of frequency 256 Hz generated and this soundwave induces vibration in the tuning fork B
due to resonance effect because frequency of tuning fork B and frequency of sound wave that induces vibration
are same.
(2) Pith ball acts as pendulam and has its own frequency that depends upon the length of pendulam.
If frequency of pendulam and frequency of tuning fork is not matching then pithball will not bounce
(3) If frequencies of tuning fork are different , there will not be resonance phenomena.
Hence sound waves from tuning fork -A will not induce vibrations in tuning fork-B

Answered by Thiyagarajan K | 26th Feb, 2021, 03:28: PM

Queries asked on Sunday & after 7pm from Monday to Saturday will be answered after 12pm the next working day.