NTNUJAVA Virtual Physics Laboratory
Enjoy the fun of physics with simulations!
Backup site http://enjoy.phy.ntnu.edu.tw/ntnujava/
July 16, 2018, 09:27:40 pm *
Welcome, Guest. Please login or register.
Did you miss your activation email?

Login with username, password and session length
 
   Home   Help Search Login Register  
Youe can not help men permanently by doing for them what they could and should do for themselves. ..."Abraham Lincoln(1809-1865, US President 1861-1865"
Google Bookmarks Yahoo My Web MSN Live Netscape Del.icio.us FURL Stumble Upon Delirious Ask FaceBook

NTNUJAVA Virtual Physics Laboratory
Enjoy the fun of physics with simulations!
Backup site http://enjoy.phy.ntnu.edu.tw/ntnujava/ > JDK1.0.2 simulations (1996-2001) > Optics > Focal length
Pages: [1]   Go Down
« previous next »
  Print  
Author Topic: Focal length  (Read 3434 times)
0 Members and 1 Guest are viewing this topic. Click to toggle author information(expand message area).
Spike
Newbie
*
Offline Offline

Posts: 1
«
Embed this message
on: April 01, 2012, 11:33:03 am » posted from:Adelaide,South Australia,Australia
A astronomical telescope is used to project a real image of the moon on the screen 25 cm from the eyepiece, which has a focal length of 5 cm. How far must the eyepiece be moved from its normal position. Can anyone help me how to work this one out Smiley
Logged
Fu-Kwun Hwang
Administrator
Hero Member
*****
Offline Offline

Posts: 3080



WWW
«
Embed this message
Reply #1 on: April 01, 2012, 03:53:38 pm » posted from:,,Satellite Provider
Hint:
It is a telescope, so the moon can be treated as an object located at infinite.
So the image is form at the focus point.

You might be able to work out the rest! :-) Cheesy
Logged
Pages: [1]   Go Up
  Print  
Youe can not help men permanently by doing for them what they could and should do for themselves. ..."Abraham Lincoln(1809-1865, US President 1861-1865"
« previous next »
 
Jump to:  


Related Topics
Subject Started by Replies Views Last post
How to make an applet that is controlled by F (length) and angle (cta)
Questions related to EJS 		lookang 4 8546 Last post March 02, 2009, 10:22:45 pm
by Fu-Kwun Hwang
Are they the same length? Why it seems to become shorter?
illusion 		Fu-Kwun Hwang 0 3339 Last post January 01, 2011, 03:25:48 pm
by Fu-Kwun Hwang
Length contraction (Special Relativity:Lorentz transformation)
Modern Physics 		Fu-Kwun Hwang 0 27008 Last post February 28, 2011, 05:47:52 pm
by Fu-Kwun Hwang
Powered by MySQL Powered by PHP Powered by SMF 1.1.13 | SMF © 2006-2011, Simple Machines LLC Valid XHTML 1.0! Valid CSS!
Page created in 0.54 seconds with 22 queries.since 2011/06/15