Need help in understanding phase angle/difference in A level physics.

[mutineer123]

I understand what a phase angle/difference is, but when it comes to applying them in questions (from past papers) my mind draws a blank. Can anyone here in simple terms, explain how can I draw let's say a phase angle difference 'precisely' of a wave in a graph?

Additional details : I am in AS level right now, so please go easy on any advanced mathematics. And just as a heads up: We have just learned a sine graph in math as well as radians( so I know a whole wavelength is 2∏.)

 

[mutineer123]

I understand what a phase angle/difference is, but when it comes to applying them in questions (from past papers) my mind draws a blank. Can anyone here in simple terms, explain how can I draw let's say a phase angle difference 'precisely' of a wave in a graph?

Additional details : I am in AS level right now, so please go easy on any advanced mathematics. And just as a heads up: We have just learned a sine graph in math as well as radians( so I know a whole wavelength is 2∏.)

I Just came across a question, which I think will help explain my doubt better

http://www.xtremepapers.com/CIE/International%20A%20And%20AS%20Level/9702%20-%20Physics/9702_w02_qp_2.pdf

here in question 5 it says " draw the variation with time t of the displacement x of the point in wave T2" So see, while I know phase angle of 60° means T2 lags behind T1 by 60( less than ∏/2 or 90°), I have no idea how to draw it.
.

 

[elliott]

The phase of a transverse wave is how far it has been translated or shifted. Think back to algebra when we translated graphs of lines by adding and subtracting numbers.

In this case, a phase of 60 degrees results in a shift of ∏/3 radians or 1/6 of a wavelength, being that one wavelength = 2∏ = 360 degrees. If the wavelength of this graph is 3 units then it will be shifted by .5 units to the left (T₂ drags behind T₁)

 

[mutineer123]

The phase of a transverse wave is how far it has been translated or shifted. Think back to algebra when we translated graphs of lines by adding and subtracting numbers.

In this case, a phase of 60 degrees results in a shift of ∏/3 radians or 1/6 of a wavelength, being that one wavelength = 2∏ = 360 degrees. If the wavelength of this graph is 3 units then it will be shifted by .5 units to the left (T₂ drags behind T₁)

Thank you elliott, no one really explained it before with translation..it was very helpful :)

 

[pmacias]

The phase angle/difference is an important concept in physics, particularly in the study of waves. It refers to the difference in the starting point of two waves that have the same frequency and amplitude. This can be seen as a measure of how much the waves are "out of sync" with each other.

To understand how to draw a phase angle difference precisely on a graph, it is important to first understand the basics of wave properties. A wave can be represented graphically as a sine or cosine function, with the horizontal axis representing time and the vertical axis representing displacement or amplitude. The wavelength is the distance between two consecutive peaks or troughs of the wave and is represented by the symbol λ (lambda). The period is the time it takes for one complete cycle of the wave and is represented by the symbol T.

To draw a phase angle difference on a graph, you need to first identify the starting point of each wave. This can be done by looking at the equation of the wave. For example, if the equation is y = A sin (ωt + φ), where A is the amplitude, ω is the angular frequency, and φ is the phase angle, then the starting point of the wave is at φ. This means that the wave starts at a displacement of A at time t = 0.

Now, if you have two waves with the same frequency and amplitude, but different phase angles, you can draw them on the same graph by starting each wave at its respective phase angle. For example, if one wave has a phase angle of 0 and the other has a phase angle of π/2, the second wave will start at a displacement of A at time t = 0. This will create a phase difference of π/2 between the two waves.

To draw the phase angle difference precisely, you can use a protractor to measure the angle between the starting points of the two waves. This angle will be equal to the phase angle difference between the two waves. Alternatively, you can also calculate the phase angle difference by dividing the wavelength by the period and multiplying it by the phase angle difference (in radians).

It is also important to note that the phase angle difference can be positive or negative, depending on the direction in which the waves are traveling. If the waves are traveling in the same direction, the phase angle difference will be positive. If they are traveling in opposite directions, the phase angle difference will be negative.

I hope this explanation helps you better understand