Go Back   Physics Help Forum > College/University Physics Help > Advanced Optics

Advanced Optics Advanced Light and Optics Physics Help Forum

LinkBack Thread Tools Display Modes
Old May 2nd 2009, 12:11 PM   #1
Junior Member
Join Date: Apr 2009
Posts: 2
trouble with optics

A diverging lens (f = -10.0cm) is located 20.0cm to the left of a converging lens (f = 30.0cm). An object stands to the left of the diverging lens, exactly at its focal point. Determine the distance (in cm) of the final image relative to the converging lens
colstu0510 is offline   Reply With Quote
Old May 3rd 2009, 09:23 AM   #2
Physics Team
Join Date: Feb 2009
Location: India
Posts: 365
The question has to be solved in two steps.
First let us find the position of the image formed by the diverging lens. For this-
u = -10 cm (as the object is placed at the focus of diverging lens)
f = -10 cm
1/v - 1/u = 1/f
1/v - 1/(-10) = 1/(-10)
This gives v = -5 cm. This means the image is formed at a distance of 5 cm and at the left side of the diverging lens.

This image will act as the object for the converging lens. The distance of this image from the converging lens is 5 +20 = 25 cm left of the converging lens. Hence for this lens-

u = -25 cm
f = 30 cm
1/v - 1/(-25) = 1/30
this gives v = -150cm. It means the final image is 150 cm from and left of the converging lens.
Parvez is offline   Reply With Quote

  Physics Help Forum > College/University Physics Help > Advanced Optics

optics, trouble

Thread Tools
Display Modes

Similar Physics Forum Discussions
Thread Thread Starter Forum Replies Last Post
Having trouble with Jupiter calculations kiwiheretic Kinematics and Dynamics 5 Aug 4th 2016 06:21 AM
basic equation trouble avengefulghost General Physics 1 Jan 10th 2011 11:11 PM
Having trouble with this... bradycat Kinematics and Dynamics 4 Sep 28th 2010 03:06 PM
trouble with kinematics rose Kinematics and Dynamics 6 Nov 3rd 2009 09:46 AM
trouble in physics, need hw help jumper Kinematics and Dynamics 1 Sep 26th 2009 09:18 PM

Facebook Twitter Google+ RSS Feed