Recent content by MrMoose

Homework Statement A goldfish in a spherical fish bowl of radius R is at the level of the center of the bowl and at distance R/2 from the glass. What magnification of the fish is produced by the water of the bowl for a viewer looking along a line that includes the fish and the center, from...

Homework Statement A beam of parallel light rays from a laser is incident on a solid transparent sphere of index of refraction n1 (see figure). (a) If a point image is produced at the back of the sphere, what is the index of refraction of the sphere? (b)What index of refraction, if any, will...

Nice, Thanks ehild! I think I got it now. Taking up from just before the incorrect equation: 90 - arcsin(sin(θa)/n1) > arcsin(n2/n1) sin[90 - arcsin(sin(θa)/n1)] > n2/n1 using the following property for sine: sin(x-y) = sinx*cosy - cosx*siny sin(90)*cos[arcsin(sinθa/n1)] -...

Homework Statement An optical fiber consists of a glass core (index of refraction n1) surrounded by a coating (index of refration n2<n1). Suppose a beam of light enters the fiber from air at an angle θ with the fiber axis as shown in attached. (a) Show that the greatest possible value of θ...

Oh wow, that was a silly mistake. So... Tan(55°) = 50cm/X1 X1 = 0.35m And X = X1 + X2 = 1.07m, which is the correct answer. Thanks so much for your help.

Great, Thanks Haruspex. So when I consider the following: θ1 = (arccos(-2*sqrt(0.1)) + 90) / 2 I get θ1 = 109.62° , which is also 19.62° off the normal. That wraps it up!

Hi mfb, please elaborate, I still don't see the error. Tangent of the angle is equal to the length of the opposite side over the length of the adjacent side.

Homework Statement In the figure attached, a 2.00m long vertical pole extends from the bottom of a swimming pool to a point 50.0cm above the water. Sunlight is incident at 55.0° above the horizon. What is the length of the shadow of the pole on the level bottom of the pool? Homework...

Thank you! I read that question over so many times and missed that part every time. I think I got it now: I1 = Io*cos^2(θ1) I2 = I1*cos^2(θ2) Where θ2 = 90 - θ1 We also know that I2 = 0.10 * Io, therefore: I2 = 0.1 * Io = Io * cos^2(θ1) * cos^2(90-θ1) Io cancels out and you...

Homework Statement A beam of polarized light is sent through a system of two polarizing sheets. Relative to the polarization direction of that incident light, the polarizing directions of the sheets are at angles θ for the first sheet and 90° for the second sheet. If 0.10 of the incident...

Thanks Nascent Oxygen, I'm having a lot of trouble visualizing this problem and radiation pressure in general. I know that Pr for a beam that is totally reflected along the original path is just dependent on the Intensity and speed of light: Pr = 2*I / c It's twice what it would be for a beam...

Homework Statement A laser beam of intensity I reflects from a flat, totally reflecting surface of area A whose normal makes an angle θ with the direction of the beam. Write an expression for the radiation pressure Pr[θ] exerted on the surface, in terms of the pressure Pr[p] that would be...

Holy smokes. Thanks. Pra + Prr = (frac)*I/c + 2*(1-frac)*I/c = I*frac/c + 2*I/c - 2*frac*I/c = (2 - frac)*I / c

Homework Statement Radiation of intensity I is normally incident on an object that absorbs a fraction frac of it and reflects the rest back along the original path. What is the radiation pressure on the object? Homework Equations Radiation pressure Pr (force/unit area) Pra = I/c...

Ok, I just got the right answer. The wave speed, v, is the speed of light, c: v = c With this knowledge, you can move on to steps 4 and 5 and get the right answer. My next question is... why? I though EM waves only travel at the speed of light through a vacuum. Should I have assumed that...