# Transverse and longitudinal waves

• smart_worker
In summary: The vertical slit will not reduce the amplitude of the longitudinal wave to zero because the particles are still moving in the direction of the wave propagation, just not in a transverse direction. This is why longitudinal waves do not exhibit polarization like transverse waves do.
smart_worker
let me make it clear this is NOT A HOMEWORK.i am just having a doubt.
if there is a rope passing through two parallel vertical slits placed close to each other. The rope is fixed and if it's moved up and down perpendicular to its length,transverse waves are generated with
vibrations parallel to the slit.But if the second slit is made horizontal, the two slits are perpendicular to each other. Now, no vibrations will pass through the second slit and amplitude of vibrations will become zero.but how is that possible?

On the otherhand, if longitudinal waves are generated in the rope by moving the rope along forward and backward, the vibrations will pass through them irrespective of their positions.

why only longitudinal waves exhibit this behaviour

smart_worker said:
if the second slit is made horizontal, the two slits are perpendicular to each other. Now, no vibrations will pass through the second slit and amplitude of vibrations will become zero.but how is that possible?

On the otherhand, if longitudinal waves are generated in the rope by moving the rope along forward and backward, the vibrations will pass through them irrespective of their positions.

why only longitudinal waves exhibit this behaviour
The phenomenon you are describing is called polarization. It is one of the distinguishing features of transverse waves that they have two polarization states and one of the distinguishing features of longitudinal waves that they have only one. That is why light waves were known to be transverse long before Maxwells equations.

smart_worker said:
let me make it clear this is NOT A HOMEWORK.i am just having a doubt.
if there is a rope passing through two parallel vertical slits placed close to each other. The rope is fixed and if it's moved up and down perpendicular to its length,transverse waves are generated with
vibrations parallel to the slit.But if the second slit is made horizontal, the two slits are perpendicular to each other. Now, no vibrations will pass through the second slit and amplitude of vibrations will become zero.but how is that possible?

On the otherhand, if longitudinal waves are generated in the rope by moving the rope along forward and backward, the vibrations will pass through them irrespective of their positions.

why only longitudinal waves exhibit this behaviour

What you have already written, more or less contains the answer to your question. It's only when you have a transverse vibration that there is any vibration away from the direction of propagation. If there is no transverse component of movement (i.e. in a longitudinal wave) then you cannot select a particular transverse 'component' in order to polarise the wave.
BTW, the rope example makes it hard to deal with the general question of polarisation at 'any angle'. It is better to consider the familiar radio (dipole) antenna, which launches waves that are polarised in the direction of the 'rods' of the antenna. A similar receiving antenna, parallel with the rods, will pick up a maximum signal. As you rotate the receiving antenna, you will pick up less and less of the signal (just receiving the component in line with the receive antenna), until you are at right angles, where there is zero component. It's an example of Vectors.

will not the amplitude of longitudinal wave become zero if it passes through vertical slit

aaaka said:
will not the amplitude of longitudinal wave become zero if it passes through vertical slit
Why should it? The slit will reduce the total flux of energy (of course - because most of the energy would be blocked by the plate with the slit in it) but that would be the case for a transverse wave too. The only particle motion will be 'through' the slit if the wave is longitudinal. Check your definitions of the different waves; that could be your problem.

sophiecentaur said:
Why should it? The slit will reduce the total flux of energy (of course - because most of the energy would be blocked by the plate with the slit in it) but that would be the case for a transverse wave too. The only particle motion will be 'through' the slit if the wave is longitudinal. Check your definitions of the different waves; that could be your problem.
in case of transverse waves as the horizontal slit rdeuces its amplitude to zero why the vertical slit don't reduces the amplitude of longitudinal waves to zero and transerve wave will pass through the vertical slit unobstructed but the longitudinal won't
the transverse wave amplitude will be zero by the horizontal slit so can"t the vertical slit zero amplitude of the longitudinal wave

Last edited:
aaaka said:
so can"t the vertical slit zero amplitude of the longitudinal wave

neither the vertical or horizontal slits will stop the longitudinal wave because neither of them are in the plane of the
oscillation of the longitudinal wave

## 1. What are transverse waves?

Transverse waves are a type of mechanical wave that move perpendicular to the direction of energy transfer. This means that the particles of the medium through which the wave is traveling vibrate up and down or side to side as the wave passes through them.

## 2. How do transverse waves differ from longitudinal waves?

Unlike transverse waves, longitudinal waves move parallel to the direction of energy transfer. This means that the particles of the medium through which the wave is traveling vibrate back and forth in the same direction as the wave itself.

## 3. What are some examples of transverse and longitudinal waves?

Transverse waves can be seen in water ripples, light waves, and seismic S waves. Longitudinal waves can be seen in sound waves and seismic P waves.

## 4. How do transverse and longitudinal waves travel through different mediums?

Transverse waves can travel through solids, liquids, and gases, but they cannot travel through a vacuum. Longitudinal waves, on the other hand, can travel through all three states of matter as well as a vacuum.

## 5. How are transverse and longitudinal waves measured and described?

The amplitude, wavelength, and frequency of a transverse wave can be measured and described. For longitudinal waves, the amplitude, wavelength, and period (inverse of frequency) can be measured and described.

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