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Question
Give two examples of forced vibrations.
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Solution
(i) The vibrations produced in the board of a guitar when its string is made to vibrate.
(ii) The vibrations produced in the tabletop when the stem of a vibrating tuning fork is pressed against it.
RELATED QUESTIONS
The adjacent diagram shows three different modes of vibrations P, Q and R of the same string.
(i) Which vibration will produce a louder sound and why?
(ii) The sound of which string will have maximum shrillness?
(iii) State the ratio of wavelengths of P and R.
The diagram above shows a wire stretched over a sonometer. Stems of two vibrating tuning forks A and Bare touched to the wooden box of the sonometer. It is observed that the paper rider (a small piece of paper folded at the centre) present on the wire flies off when the stem of vibrating tuning fork B is touched to the wooden box but the paper just vibrates when the stem of vibrating tuning fork A is touched to the wooden box.
1) Name the phenomenon when the paper rider just vibrates.
2) Name the phenomenon when the paper rider flies off.
3) Why does the paper rider fly off when the stem of tuning fork B is touched to the box?
When a troop crosses a suspension bridge, the soldiers are asked to break steps. Explain the reason.
State two ways in which resonance differs from forced vibrations.
The rearview mirror of a motorbike starts vibrating violently at some particular speed of the motorbike, what could be done to stop the violent vibrations.
Explain why are soldiers asked to walk out of step while crossing bridges?
Explain a person walking past a railway line, in the middle of night hears a ringing sound along with the sound of his footsteps.
A string stretched between its ends is made to vibrate by placing the stem of a vibrating tuning fork at its one end. State three ways how you will increase the frequency of note produced by the string.
What are the factors that affect the frequency of a vibrating string and how do they affect the frequency?
What do you understand by free vibrations of a body? Draw a displacement-time graph to represent them. Given one example.
