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Re: Optics B/C

Posted: November 4th, 2016, 5:59 pm
by John Richardsim
Alex-RCHS wrote:New to the forum... I hope I'm doing this "hide" thing right.

Answer: ~~When the angle of incidence is greater than the critical angle.~~

Edit: I'm not. Apologies.
Yeah, when using hide boxes, what text appears automatically and what text is hidden must be separated by the "|" symbol (you have to have something be automatically visible, so if you put ".|(your answer)" in the hide syntax you would get:)
When the angle of incidence is greater than the critical angle.
But yeah, you're correct. Your turn.

Re: Optics B/C

Posted: November 4th, 2016, 6:38 pm
by Alex-RCHS
When light moves from a vacuum to a certain piece of glass its velocity slows to 1.98 x 10^8 meters per second. What is the index of refraction of the piece of glass?

Re: Optics B/C

Posted: November 4th, 2016, 6:55 pm
by Adi1008
Alex-RCHS wrote:When light moves from a vacuum to a certain piece of glass its velocity slows to 1.98 x 10^8 meters per second. What is the index of refraction of the piece of glass?
[math]c = 3 \times 10^8 m/s, v = 1.98 \times 10^8 m/s, n= \frac{c}{v} = 1.52[/math]

Re: Optics B/C

Posted: November 5th, 2016, 7:26 am
by Alex-RCHS
Correct! Your turn.

Re: Optics B/C

Posted: November 6th, 2016, 7:10 pm
by Adi1008
A source of light is located at a distance of 0.72m below the surface of water (n = 1.33). The light emerges at the surface into air (n=1.00) after undergoing refraction at the surface. Show that all the emerging light is all within a circle at the surface, and calculate the radius of the circle.

Also, sorry for taking so long to respond :/

Re: Optics B/C

Posted: November 12th, 2016, 8:25 am
by John Richardsim
Adi1008 wrote:A source of light is located at a distance of 0.72m below the surface of water (n = 1.33). The light emerges at the surface into air (n=1.00) after undergoing refraction at the surface. Show that all the emerging light is all within a circle at the surface, and calculate the radius of the circle.

Also, sorry for taking so long to respond :/
0.82m

Re: Optics B/C

Posted: December 1st, 2016, 6:34 pm
by Adi1008
Yup, that's correct. Sorry for such a late response!

Re: Optics B/C

Posted: December 1st, 2016, 6:45 pm
by John Richardsim
What is the power of a lens with a focal length of 8.40 centimeters?

Re: Optics B/C

Posted: December 1st, 2016, 7:22 pm
by Fluorine
John Richardsim wrote:What is the power of a lens with a focal length of 8.40 centimeters?
Power (D) = 100/Focal Length (cm)

Sooo approx: 11.9 dioptres

Re: Optics B/C

Posted: December 2nd, 2016, 1:31 pm
by John Richardsim
Fluorine wrote:
John Richardsim wrote:What is the power of a lens with a focal length of 8.40 centimeters?
Power (D) = 100/Focal Length (cm)

Sooo approx: 11.9 dioptres
Good, your turn.