Critical angle and minimum angle of incidence for light in ice

[max1995]

Homework Statement

Light traveling thorugh air is at incident at point x on the block of ice. If the refractive index is 1.3, calculate
a) the critical angle at the ice-air interface (3 marks)
b) the minimum angle of incidence, for the light to Y refracted out of the block at any point along the top surface (7 marks)

Homework Equations

The Attempt at a Solution

a) sin(θ_c)=1/n_m
θ= sin^-1(1/1.3)
θ= 50.3 (1 d.p)

is this right?

b) Need help on this one

 

[NascentOxygen]

(a) is right.

For (b) there's a diagram to accompany it?

 

[max1995]

(a) is right.

For (b) there's a diagram to accompany it?

yep it is in the file i uploaded

 

[max1995]

thank you for helping btw :)

 

[NascentOxygen]

I can view only jpegs, sorry.

 

[max1995]

I can view only jpegs, sorry.

Managed to turn it into jpeg

 

[NascentOxygen]

I was anticipating there'd be a point Y. I find there is not.

Perhaps you meant to type
b) the minimum angle of incidence, for light to be refracted out of the block at any point along the top surface[/color]?

If so, start by drawing a large diagram with all straight lines (e.g., by using a ruler).

By "any point" I think they don't mean "every point", just at least some point.