1. Set the demonstration so you are using a CONVEX LENS with focal length of 40 cm.
2. Move the object until it is 120 cm from the LENS.
3. Notice the location and size of the image.
4. Now move the object toward the LENS until it is located at 2f (which is 80 cm.) It is important that you keep the object the same size while you are moving it.
5. Describe what happened to the location and size of the image as the object moved from 120 cm to 80 cm. Put your answer in the box below.
   
   
6. Now continue to move the object from 80 cm in toward the LENS until it is almost at the focus (40 cm). Describe what happens to the location and size of the image as the object moves toward the focus. Place your answer in the box below.
   
   
7. Now continue to move the object from the focus in toward the LENS. Describe what happens to the location and size of the image as the object moves from the focus toward the LENS. Place your answer in the box below.
   
   
8. As the object moved from 40 cm in to the lens when was the image real and when was it virtual? Type your answer in the box below.
   
   
9. Which of the following is true about images?
   Real images can be seen. Virtual images are not real and therefore can not be seen.
   Both real and virtual images can be seen. Virtual images can be projected on a screen. Real images can not be projected on a screen.
   Both real and virtual images can be seen. Real images can be projected on a screen. Virtual images can not be projected on a screen.
   I don't have the first clue about images and wish you would stop asking these questions.
   

Indicate your section by using the buttons at the top of the page. DO NOT EDIT the text in this box:

Click here to return to the contents page.