Hey there! Sign in to join this conversationNew here? Join for free
Turn on thread page Beta
    • Thread Starter
    Offline

    16
    ReputationRep:
    This is kind of related to physics but it is mainly maths so i'll post it here. I have worked out the critical angle to be 75.2 degrees (if that has any relevance?!)

    How do you work out angle i? It is only worth one mark so i assume its quite simple but nevertheless, I'm a bit confused. Thanks Name:  ImageUploadedByStudent Room1446836780.896163.jpg
Views: 64
Size:  135.1 KB


    Posted from TSR Mobile
    Offline

    6
    ReputationRep:
    (Original post by jessyjellytot14)
    This is kind of related to physics but it is mainly maths so i'll post it here. I have worked out the critical angle to be 75.2 degrees (if that has any relevance?!)

    How do you work out angle i? It is only worth one mark so i assume its quite simple but nevertheless, I'm a bit confused. Thanks Name:  ImageUploadedByStudent Room1446836780.896163.jpg
Views: 64
Size:  135.1 KB


    Posted from TSR Mobile
    You should know that, by the law of reflection, the angle of incidence = the angle of reflection. Apply that to the 85 degrees and you will get the top left angle in the triangle. Then it is just subtraction from 180 degrees to get the required angle
    • Thread Starter
    Offline

    16
    ReputationRep:
    (Original post by PhyM23)
    You should know that, by the law of reflection, the angle of incidence = the angle of reflection. Apply that to the 85 degrees and you will get the top left angle in the triangle. Then it is just subtraction from 180 degrees to get the required angle
    So would angle i and angle r both be 65 degrees?
    Offline

    6
    ReputationRep:
    (Original post by jessyjellytot14)
    So would angle i and angle r both be 65 degrees?
    Almost - you are correct in saying that angle i = 65 degrees, but at this stage you will need to use Snell's Law [n1sin(theta1) = n2sin(theta2)] in order to get r, since refraction, not reflection, is taking place at this point
 
 
 
Reply
Submit reply
Turn on thread page Beta
Updated: November 6, 2015
Poll
“Yanny” or “Laurel”
Useful resources

Make your revision easier

Maths

Maths Forum posting guidelines

Not sure where to post? Read the updated guidelines here

Equations

How to use LaTex

Writing equations the easy way

Student revising

Study habits of A* students

Top tips from students who have already aced their exams

Study Planner

Create your own Study Planner

Never miss a deadline again

Polling station sign

Thinking about a maths degree?

Chat with other maths applicants

Can you help? Study help unanswered threads

Groups associated with this forum:

View associated groups

The Student Room, Get Revising and Marked by Teachers are trading names of The Student Room Group Ltd.

Register Number: 04666380 (England and Wales), VAT No. 806 8067 22 Registered Office: International House, Queens Road, Brighton, BN1 3XE

Write a reply...
Reply
Hide
Reputation gems: You get these gems as you gain rep from other members for making good contributions and giving helpful advice.