What do we need a protractor for in physics? (1 Viewer)

[Shoom]

List all types of questions/topics were a protractor is needed.
thanks.

 

[cd285]

errr...calculating the angle of incidence/refraction in the waves topic...thats pretty much for the prelim

 

[youngminii]

I did my Physics exam and the only question I used my protractor for was the..
The Angle of Incidence thingo (I ended up getting it wrong anyways)

The one where there's 2 mediums. The light gets refracted when it travels from medium A into medium B

Sini/Sinr
Angle of Incidence and the whole Refraction Index thingo
Worth about 5 marks in my test

 

[Shoom]

Could you go into that question in your exam in a little more detail, what exactly was it asking, and what did you use the protractor for?

If I was to measure angles of incidine or r, I measure them from the normal right?

 

[Timothy.Siu]

Could you go into that question in your exam in a little more detail, what exactly was it asking, and what did you use the protractor for?

If I was to measure angles of incidine or r, I measure them from the normal right?

yes u do

 

[Shoom]

Ok, this crap to say, but I forgot how to use my protractor, if I have a normal and I want to measure the angle where do I put the protractor? Can someone provide images to help lol.

 

[Timothy.Siu]

Ok, this crap to say, but I forgot how to use my protractor, if I have a normal and I want to measure the angle where do I put the protractor? Can someone provide images to help lol.

lol....ur beyond help

 

[Shoom]

Problem

Angle of Incidence is 40 calculate the angle of refraction. Light enters perspex from air.

Refractive index of perspex= 1.46 light = 1
Velocity of perspex in medium = 2 x 10^8 light = 3 x 10^8

Using snells law

Sin40/Sinr=3x10^8/2x10^8

Sinr= 2x10^8xSin40/3x10^8 = 0.4285

Shift Sin 0.4285= 25.37 degrees.


HOwever when I use
Sini/Sinr=n2/n1

Sin40/Sinr= 1.46/1

Sin40/1.46= Sin r = 0.4402
Shift Sin 0.4402=26.12 degrees, why do I get this difference, when snells law states V1/v2=sini/sinr=n2/n1

Will I get this wrong in exam if I use either method but get a different answer?

 

[youngminii]

Problem

Angle of Incidence is 40 calculate the angle of refraction. Light enters perspex from air.

Refractive index of perspex= 1.46 light = 1
Velocity of perspex in medium = 2 x 10^8 light = 3 x 10^8

Using snells law

Sin40/Sinr=3x10^8/2x10^8

Sinr= 2x10^8xSin40/3x10^8 = 0.4285

Shift Sin 0.4285= 25.37 degrees.


HOwever when I use
Sini/Sinr=n2/n1

Sin40/Sinr= 1.46/1

Sin40/1.46= Sin r = 0.4402
Shift Sin 0.4402=26.12 degrees, why do I get this difference, when snells law states V1/v2=sini/sinr=n2/n1

Will I get this wrong in exam if I use either method but get a different answer?

I don't understand, the perspex IS the medium
Anyways, obviously the answer should be equal.. Which means you're doing something wrong

 

[Shoom]

They gave me the wrong information the refractive index of perspex should be 1.5. So yeah, hey did you have any questions in your physics exam relating to the superposition of waves or vectors?

 

[youngminii]

Uhh, not in mine
But mine's independent so..