Lens Refraction Problems: Help with Calculating Image Distance and Magnification

[moonlit]

I'm really not sure how to figure these 3 problems out. Can someone please help me. Thanks.

1) A converging lens has a focal length of 85 cm. A 14-cm-tall object is located 121 cm in front of this lens. (a) What is the image distance? (b) What is the image height? Be sure to include the proper algebraic sign.

2) An object is located 38.2 cm to the left of a converging lens whose focal length is 59.2 cm. (a) Determine the image distance and (b) the magnification.

3) An object is 27 cm in front of a diverging lens that has a focal length of -14 cm. How far in front of the lens should the object be placed so that the size of its image is reduced by a factor of 2.1?

 

[Doc Al]

apply the lens equation

These are all straightforward applications of the lens equation. https://www.physicsforums.com/showpost.php?p=187207&postcount=2

Give them a try!

 

[moonlit]

I got the last one but the other two I'm still unsure of...

 

[Doc Al]

If you would like some help, show your work and I'll take a look.

 

[moonlit]

Nevermind, I figured it out. Thanks anyway!