Hi in question 3)b) you used trignometry to calculate T and then simply drew the diagram again with the calculated value of T. Doesn't the question explicitly ask you to USE A VECOTR DIAGRAM to find T?
Thank you. I think the answer of question 8 is incorrect. Wavefronts should be the other way round because the wavelength must be greater in air than in ice. The correct way to do it is NOT to refract the wavefronts themselves, you should refract the line that is perpendicular to the wavefronts (also draw your own perpendicular line because the one in the question that says ‘direction of wave’ is not perpendicular).
yes, change of medium from ice to air of light waves means increase in wavelength as well, but here the question does not require candidates to show this.I hope this clarifies your doubt
Your very much right man. The answer in this video for question 8 is completely wrong. I suggest you draw the refracted which is bending away from normal and then draw wavefronts perpendicular to the refracted ray
The answer in this video for question 8 is completely wrong. It must be drawn such that the refracted ray is bending away from normal and then draw wavefronts perpendicular to the refracted ray. Because it is moving from region of low speed to region of higher speed. Hence you will be have a greater wavelength
This is the answer from the respective mark scheme: Wavefronts in the air: Parallel to each other [B1] Make a larger angle with the boundary than wavefronts in ice and from top left to bottom right [B1] At least one wavefront meets a wavefront in ice at the boundary [B1] It does not credit wavelength. However, you can show greater wavelength if you wish to.
@@examhelpweb2090 according to the marking scheme it says Make a larger angle with the boundary than wavefronts in ice and from top left to bottom right shouldnt it be closer to the normal ?
@@zainabkhan6263 it should draw the ray that represents the direction of the wave first away from the normal and then draw the wave fronts perpendicular to that as it s a transverse wave
@@examhelpweb2090 Thank you for the quick response. Your video helped me well for Physics. Without this, I cannot understand anything. As Answer keys didn't show full steps.
igcse requires you to round off the values to the same ones in the eqution values (like 1945 tkg should be written a 2000 kg if the densicy is 400 (one significant figure))
In question 8 I think we should show that wavelength is increasing , light rays should turn away from boundary .
Nah
Hi in question 3)b) you used trignometry to calculate T and then simply drew the diagram again with the calculated value of T. Doesn't the question explicitly ask you to USE A VECOTR DIAGRAM to find T?
bro ethics isn't gonna take you anywhere, this is IGCSE
Yea you have to use vectors
Itsnot that serious unless in the question it was stated in bole, other wise a trig triangle is a vector diagram aswell.
Thank you. I think the answer of question 8 is incorrect. Wavefronts should be the other way round because the wavelength must be greater in air than in ice. The correct way to do it is NOT to refract the wavefronts themselves, you should refract the line that is perpendicular to the wavefronts (also draw your own perpendicular line because the one in the question that says ‘direction of wave’ is not perpendicular).
hi for question 8, shouldnt the wavelength increase as light travels faster in air?
yes, change of medium from ice to air of light waves means increase in wavelength as well, but here the question does not require candidates to show this.I hope this clarifies your doubt
Your very much right man. The answer in this video for question 8 is completely wrong. I suggest you draw the refracted which is bending away from normal and then draw wavefronts perpendicular to the refracted ray
@@jailnet thats very true, we use rays to determine the angles
The answer in this video for question 8 is completely wrong. It must be drawn such that the refracted ray is bending away from normal and then draw wavefronts perpendicular to the refracted ray. Because it is moving from region of low speed to region of higher speed. Hence you will be have a greater wavelength
This is the answer from the respective mark scheme:
Wavefronts in the air:
Parallel to each other [B1]
Make a larger angle with the boundary than wavefronts in ice and from top left to bottom right [B1]
At least one wavefront meets a wavefront in ice at the boundary [B1]
It does not credit wavelength. However, you can show greater wavelength if you wish to.
@@examhelpweb2090 according to the marking scheme it says Make a larger angle with the boundary than wavefronts in ice and from top left to bottom right shouldnt it be closer to the normal ?
@@zainabkhan6263 it should draw the ray that represents the direction of the wave first away from the normal and then draw the wave fronts perpendicular to that as it s a transverse wave
Off topic question.
What's the PDF software name?
Thank you in advance.
It's PDF Reader Pro.
@@examhelpweb2090 Thank you for the quick response.
Your video helped me well for Physics.
Without this, I cannot understand anything.
As Answer keys didn't show full steps.
Answer to question 2(1)1 is wrong it should be 31200
Yes that is the exact answer however, according to the mark scheme all answers are corrected to 2 significant figures.
A tually ur the one wrong I mean ur answer is right but Cambridge requires us to write in 2 sf
hi why don t u explain the answers why do u just answer them sum of them i have to memorize because i dont understand.:/
Could you tell us the exact Q that you don't understand or feel should have been explained further?
thank u
Great video!
Pls fix your mic
why u convert 5 minutes into seconds?
because the unit for time is seconds
No 2 is so wrong the answer is 3993600
Although the answer is 3993600J and you can write it that way, it can be rounded to two significant figures too.
igcse requires you to round off the values to the same ones in the eqution values (like 1945 tkg should be written a 2000 kg if the densicy is 400 (one significant figure))
Pls learn maths u just solve the second question wrong