Use ray tracing to determine the location of the image

[jlmessick88]

Homework Statement

An object is 6.0 cm in front of a converging lens with a focal length of 10 cm. Use ray tracing to determine the location of the image. Is the image upright or inverted? Is it real or virtual?

The Attempt at a Solution

According to my ray tracing...there is no image at all...i'm pretty sure that this is correct, but i just wanted to make sure that what I'm doing is correct??

 

[negitron]

Now way to tell without seeing your drawing.

 

[jlmessick88]

well the focal point is behind the object...
then when drawing the ray parallel to the axis, the special ray will refract through the far focal point...
the ray through the center of the lens, the ray does not bend, just continues through the lens at a straight line...
these two lines never converge...
and then the ray through the near focal point...well you can't do that since the focal point is behing the object itself...
thus no lines ever converge

 

[Doc Al]

When using ray diagrams to find the image, be sure to extend the final rays in both directions. In your example the rays will converge on the same side of the lens as the object.

 

[jlmessick88]

how could they converge on the same side of the lens as the object
if i draw the ray through the near focal point (which is behind the image itself) the ray would be pointed downward...
the two other rays, if drawn in the same direction (behind the image) they don't converge

 

[jlmessick88]

here is an image of my ray tracing

 

[Doc Al]

how could they converge on the same side of the lens as the object

You must extend them to the left, then you'd see them converge nicely.

Here's how to draw the ray diagram properly: http://hyperphysics.phy-astr.gsu.edu/Hbase/geoopt/raydiag.html#c2"

 

[jlmessick88]

oh wow...i didn't know i could do that...thanks!