I dont understand the concept of resonance and natural frequency,someone please help me with this!!..?

Question

what is resonance,is it something related to sound or just vibrations??Also,how do u determine an object's natural frequency,in the sense,with what basis it is determined??if u could explain with more simpler terms,it would be greatly appreciated!
Thanx in advance..!!

Answer 1

Suppose you had a guitar with only two strings. They are both tuned to the same pitch, and you can tell by plucking them both, one at a time, and listening.



If you pluck one string, the vibrations of that string go through the air and they will make the other string vibrate. You can then 'damp' the string you plucked (put a finger on it to stop it) and the other string will still make the same note.



This is called a 'sympathetic vibration'. In fact sitars and some other instruments have strings that only work this way, they are never plucked, they only vibrate when another string is plucked at the same pitch. They are called 'sympathetic strings'.



Now why does this happen? Imagine you're pushing a child in a swing. You are only pushing during perhaps 10% of the swing's stroke. But the swing swings at a certain frequency, based on its length. And you have to push at the right frequency. You watch the swing as it comes back, and when it begins to go forward you push it. If you pushed it at any other time, you wouldn't keep it going. So this is another form of 'sympathetic' vibration. You are pushing at the swing's resonant frequency, just as one guitar string was making the other vibrate at its resonant frequency.

Answer 2

Natural Frequency:Consider a mass m hung by a spring.Now just slightly stretch the spring and leave.The mass will start up-down harmonic motion.The frequency of oscillation will be



n=(1/2pi).sqrt(k/m)

mass of the block and k=spring constant.

Another example is of simple pendulum its frequency is

n=(1/2pi).sqrt(g/l) g=accn due to gravity.l=length of pendulum



the fact to be noticed here is this frequency purely depends on system parameters(k,l,g,m etc)

Now resonance is a phenomena when on natural frequency if we superimpose a periodic force of the same frequency,then system will oscillate with the natural frequency but amplitude will be large so more intensity.Take for example guitar or Sitar.Now when we pluck the string it vibrates at its natural frequency,but the air in sound Box will also star vibrating with the same frequency because the oscillating string passes on it vibration to the air inside the box.Now if the box dimensions are such that its natural frequency is equal to string's then we have a resonant vibration of air inside the box and we here amplified sound.

Answer 3

all terms relating to vibrations. a resonance frequency is one of many frequencies an object may vibrate at that yeilds phenomenal amplitudes compared to other frequencies. it has to do with the fact that at these frequencies, the object stores and converts kinetic\potential energy more readily than other frequencies



resonant frequencies and natural frequencies are the same thing. an easy way in practice to determine such things (if we consider a wine glass) is to tap the wine glass, it will naturally vibrate at a resonant frequency. if you match this frequency, and with sufficient power in your voice, you can shatter the glass.

Answer 4

All the atoms of every kind of matter are in vibrating mode. I.e. Every atom is vibrating with some frequency this is called there natural frequency. The frequency with which any matter vibrates naturally easily is called its natural frequency. Now what is resonance . Consider a simple pendulum vibrating naturally at 23Htz frequency now its the natural freq. Of pendulum with which it vibrates naturally already it con be anything. Now he you push the bob of pendulum at the time of pendulum's forward motion and pull it at the time of backward motion i.e. Your timing of pushing and pulling the pendulum matches the natural freq. Of pendulum. Now up frequency of pushing and pulling matches the timing of pendulum's to and fro motion so your force resonate with the pendulum and as a result of this resonance the amplitude and freq. Of pendulum increases. And pendulum vibrates with resonate freq.. Now if your force freq. Doesn't matches with pendulum's natural freq. I.e. You pull at the time of forward motion and push at backward motion is any other case the frequency of pendulum decreases i.e. Don't resonate. I.e. To resonate the natural freq. And the frequency with which you resonate should match.

Answer 5

search 'resonance' on wikipedia.....