Physics Help Forum optics problems: Lens' Law

 Light and Optics Light and Optics Physics Help Forum

 Mar 29th 2009, 12:42 PM #1 Junior Member   Join Date: Oct 2008 Posts: 5 optics problems: Lens' Law A flashlight on the bottom of a 4.25 m deep swimming pool sends a ray upward and at an angle so that the ray strikes the surface of the water 2.50 m from the point directly above the flashlight. What angle (in air) does the emerging ray make with the water's surface? and A submarine is 308 m horizontally out from the shore and 110 m beneath the surface of the water. A laser beam is sent from the sub so that it strikes the surface of the water at a point 228 m from the shore. If the beam just strikes the top of a building standing directly at the water's edge, find the height of the building. They are really the same problem, I can't plug in a value greater than one for the sin-1 when using Lens' law. I'm not sure how to proceed with either one when I get there. Thank you.
 Mar 30th 2009, 02:40 AM #2 Senior Member   Join Date: Apr 2008 Location: HK Posts: 886 Use tan to find the angle i and apply Snell's law to find angle r. 1sin r = 1.34sin i Help you with the first question and you can do the second one Attached Thumbnails   Last edited by werehk; Mar 30th 2009 at 02:40 AM. Reason: give detail

 Tags law, lens, optics, problems

 Thread Tools Display Modes Linear Mode

 Similar Physics Forum Discussions Thread Thread Starter Forum Replies Last Post kenny1999 Light and Optics 0 Nov 12th 2010 06:22 AM quick.on.my.feet Light and Optics 3 Nov 5th 2009 10:48 PM dank420 Light and Optics 4 Sep 9th 2009 10:29 PM abhishek arora Light and Optics 1 Jul 3rd 2009 09:25 AM newton888 Light and Optics 0 Dec 15th 2008 07:51 PM