Amplitude, Time Period and Frequency of a Vibration

On a hot summer day, a little mosquito produces a warning sound near your ear by vibrating its wings at the rate of $3,000$wing beats per five seconds. State the frequency, in hertz, of this sound.

A child pushed his cradle for play and started learning numbers by counting the oscillations of his cradle. He counted one number per one oscillation starting from $1$, then find the number of numbers the child learned and cradle frequency of oscillations for the total time of $60$ second, if the time period of the cradle is $2.5 \mathrm{s}$.

The audible range of frequency is $20 \mathrm{Hz}$ to $20,000 \mathrm{Hz}$. Determine the corresponding range of time periods of vibrations.

The time period of a simple pendulum is given by the formula, $T=2\mathrm{\pi }\sqrt{\frac{\mathrm{l}}{\mathrm{g}}}$, where $T=$ time period, $l=$ length of pendulum and $g=$acceleration due to gravity.

If the length of the pendulum is decreased to $\frac{1}{4}$ of its initial value, then what happens to its frequency of oscillations?

A graph is drawn between the displacement and time taken for the oscillations of a simple pendulum.

The frequency of oscillation is _____$\mathrm{Hz}$.

Aditi hangs four steel dishes of the same size but different thickness.
She hits each of them with an iron rod.

The thicker the dish, the lower will be the vibration. Which dish will produce the loudest sound when hit?

Which of the following voices is likely to have minimum frequency?

The time period of a simple pendulum is $0.25 \mathrm{s}$. Calculate the frequency of the pendulum. 

During the class prize-giving ceremony, Anand clapped his hands hard while Kumar clapped his hands softly. Everybody could hear Anand's clapping while only a few could hear Kumar's clapping. This was because the sound produced by Anand was of

While drinking a soft drink, Ram starts blowing into the mouth of the bottle and finds that it makes a sound. He challenges his friend Riya to make a sound of the same pitch using her bottle, which was smaller in size. In which of these arrangements will that happen?

The sound wave is a longitudinal wave. Longitudinal waves are those waves in which the particles of the medium vibrate parallel or antiparallel along the direction of propagation of the wave. The longitudinal wave travels with the formation of 'rarefactions' and 'compressions'. Compression is the part of the wave in which the particles of the medium are closer than they normally are. Here, the density of the medium is more than the normal density and volume decreases momentarily. Rarefaction is that part of the wave in which the particles of the medium are farther apart than they normally are. Here, the density of the medium is less than the normal density and the volume increases momentarily. 

In the figure given, compared to wave P, wave Q would be _____.

The unit used for measuring the intensity of sound is decibel. The faintest sound that the human ear can detect is assigned a value of 0 decibels. Study this table and answer the question. Psychologists believe that if one sound source has10 times the power of another sound source, we hear the first about twice as loud - thus its decibel value will be double. If the decibel value of the sound from a 50W source is 60 dB, what would be the approximate decibel value of the sound from a loud 2500W source?

If a simple pendulum makes $20$ oscillations in $4$ seconds, what is its frequency? 

The following graphs show the signals recorded by a microphone for two different sounds, $A$ and $B$ is

Which statement is true?

How will you differentiate the amplitude and frequency of different sounds? Give two suitable examples from your daily life.

An object completes $20$ oscillations in ten seconds. Find its frequency and time period.

The sound from a mosquito is produced when it vibrates its wings at an average rate of $500$ vibrations per second. What is the time period of the vibration?

If a simple pendulum oscillates $10$ times in $10$ second, what would be its frequency in $\mathrm{Hz}$ ?

How can we differentiate sound on the basis of their amplitude and frequency?

A simple pendulum completes $420$ oscillation in $2 \mathrm{minutes}$. Calculate the time period and frequency.