Question

In Fig. 7.15, A, B, C and D are the four pendulums
suspended from the same
elastic string XY. The
lengths of pendulum A
and D are equal, while
the length of pendulum B
is shorter and of the
pendulum C is longer.
The pendulum A is set
Fig. 7.15
into vibrations.
(a) What is your observation about the vibrations c
pendulum D ? (b) Give reason for your observatio
in part (a). (C) What type of vibrations take place i
pendulums B and C ? (d) Give reason for the answ
in part (c).​

Answer 1

Answer:

a. pendulum C vibrates with smaller amplitude.

Since pendulum D and A are of same length

the vibrate with the same amplitudes.

b. the natural frequency of Pendulum B is equal to the frequency of vibration of Pendulum A since both are of equal length. so, the forced vibration caused in pendulum B are in resonance with vibrations of Pendulum A. on the other hand the natural frequency of Pendulum C is higher while of D is smaller than that of Pendulum A. vibrates with the same frequency of Pendulum A bit smaller amplitude due to forced vibration