Edexcel PHYSICS Doubts

[GodOfWar]

I have a question :

http://www.scribd.com/doc/46124612/Physics-Jun-2010-Actual-Exam-Paper-Unit-4

Question 4
The answer's D, but how do you get there?

It's June 2010 Unit 4 By the way

[elemis]

I have a question :

http://www.scribd.com/doc/46124612/Physics-Jun-2010-Actual-Exam-Paper-Unit-4

Question 4
The answer's D, but how do you get there?

It's June 2010 Unit 4 By the way

E_k = 0.5mv²

P²/2m = 0.5mv²

Moving the 0.5 to the other side :

P²/2m  ÷ 0.5 = mv^2

Hence, simplifying to the answer in D.

[GodOfWar]

What does the word derivation mean here? I thought we had use derivatives 

[elemis]

What does the word derivation mean here? I thought we had use derivatives 

You can derive a formula from an already known relationship.

Derive = Prove in this case.

[GodOfWar]

Thanks man

[The Golden Girl =D]

Hey can someone explain to me what is in the Photo but in a bit more detail.

Attached.

than you in advance =]

[elemis]

Hey can someone explain to me what is in the Photo but in a bit more detail.

Attached.

than you in advance =]

On it.

[elemis]

Two coherent sources of sound/light/water waves produce waves that impact on a screen.

The path difference is the difference in distance covered by the waves travelling from the source to the screen.

If Wave A from speaker A travels 10 m to get to a point on a screen and Wave B from speaker B travels 20 m to get to the SAME POINT, the path difference is 10 m. P.D. is usually expressed in terms of wavelengths. If the wavelengths of A and B were 5m then the P.D. can be said to be 2 lambda.

When the P.D = 0 phase difference = 0 hence constructive interference occurs i.e. the two waves superimpose such that the vector sum of their amplitudes leads to a doubling of amplitude.

When P.D. = whole no. of  wavelengths constructive interference occurs.

When P.D. = non-integer, half wavelengths you have destructive interference.

[The Golden Girl =D]

I got it God bless you =]

[The Golden Girl =D]

Dispersion of light :

Well there is this little thing I don't get :S Which is the following sentence ;

the glass prism offers LESS refractive index for RED color which has  a GREATER wavelength and offers LARGER refractive index for VIOLET color having SMALLER wavelength.

it's is the SAME prism *GLASS prism* so how can it give slightly differenct refractive indices for different colors o.0 ?!..... I know the idea of refractive index being INVERSELY proportional to wavelength but I just don't get the refractive index being different for different colors part.

Thank you in advance.

[elemis]

Dispersion of light :

Well there is this little thing I don't get :S Which is the following sentence ;

the glass prism offers LESS refractive index for RED color which has  a GREATER wavelength and offers LARGER refractive index for VIOLET color having SMALLER wavelength.

it's is the SAME prism *GLASS prism* so how can it give slightly differenct refractive indices for different colors o.0 ?!..... I know the idea of refractive index being INVERSELY proportional to wavelength but I just don't get the refractive index being different for different colors part.

Thank you in advance.

Check your source again. I think you've misread/misunderstood the given statement.

[Amelia]

Dispersion of light :

Well there is this little thing I don't get :S Which is the following sentence ;

the glass prism offers LESS refractive index for RED color which has  a GREATER wavelength and offers LARGER refractive index for VIOLET color having SMALLER wavelength.

it's is the SAME prism *GLASS prism* so how can it give slightly differenct refractive indices for different colors o.0 ?!..... I know the idea of refractive index being INVERSELY proportional to wavelength but I just don't get the refractive index being different for different colors part.

Thank you in advance.

I found something.  I do hope this explains it.


The index of refraction values are dependent upon the frequency of light. For visible light, the 'n' (refractive index) value does not show a large variation with frequency, but nonetheless it shows a variation. For instance, the 'n' value for frequencies of violet light is 1.53; and the 'n' value for frequencies of red light is 1.51. The absorption and reemission process causes the higher frequency (lower wavelength) violet light to travel slower through crown glass than the lower frequency (higher wavelength) red light. It is this difference in 'n' value for the varying frequencies (and wavelengths) that causes the dispersion of light by a triangular prism. Violet light, being slowed down to a greater extent by the absorption and reemission process, refracts more than red light. Upon entry of white light at the first boundary of a triangular prism, there will be a slight separation of the white light into the component colors of the spectrum. Upon exiting the triangular prism at the second boundary, the separation becomes even greater and ROYGBIV is observed in its splendor.

http://www.physicsclassroom.com/class/refrn/u14l4a.cfm

 

[The Golden Girl =D]

I found something.  I do hope this explains it.


The index of refraction values are dependent upon the frequency of light. For visible light, the 'n' (refractive index) value does not show a large variation with frequency, but nonetheless it shows a variation. For instance, the 'n' value for frequencies of violet light is 1.53; and the 'n' value for frequencies of red light is 1.51. The absorption and reemission process causes the higher frequency (lower wavelength) violet light to travel slower through crown glass than the lower frequency (higher wavelength) red light. It is this difference in 'n' value for the varying frequencies (and wavelengths) that causes the dispersion of light by a triangular prism. Violet light, being slowed down to a greater extent by the absorption and reemission process, refracts more than red light. Upon entry of white light at the first boundary of a triangular prism, there will be a slight separation of the white light into the component colors of the spectrum. Upon exiting the triangular prism at the second boundary, the separation becomes even greater and ROYGBIV is observed in its splendor.

http://www.physicsclassroom.com/class/refrn/u14l4a.cfm

 

lia -Thanks it helped me link my ideas =D 

Ari - nope it's correct but it seems I forgot that there is the equation ;

lamda 1/lamda 2 = refractive index ..meaning wavelength is what varies the refractive in this case.

lamda 1 -> in air/vaccum
lamda 2 -> in medium

[mayisha]

If any1s takin edexcel a2 physics, can u plz plz plz see the questions at the end of the particle ccelerator chapter? It has 2 questions, 1 abt the cyclotron, n da other abt the LHC... i cant match my first answers to the book's, I just dunno wat on earth um doin wrong ... can sum1 plz plz plz try their hand at the sum ? Thanks a ton

[red_911]

hey can anyone tell me the approximate wavelength of all the electromagnetic radiation ? there are different values written on different websites ...
thanksss alot in advance