Finding object distance with only the focal length and magnification?

Click For Summary
SUMMARY

The discussion focuses on calculating the object distance for a diverging lens with a focal length of -13.0 cm and a desired magnification of +5.00. The relevant formulas used include the magnification equation (magnification = v/u) and the lens formula (1/f = 1/v - 1/u). By substituting the known values into these equations, users can determine the necessary object distance to achieve the specified magnification.

PREREQUISITES
  • Understanding of lens formulas, specifically for diverging lenses
  • Familiarity with magnification concepts in optics
  • Basic algebra skills for manipulating equations
  • Knowledge of sign conventions in optics
NEXT STEPS
  • Study the lens formula for different types of lenses, including converging and diverging lenses
  • Learn about the sign conventions used in optics to avoid common mistakes
  • Explore practical applications of magnification in optical devices
  • Investigate how to derive the relationships between object distance, image distance, and focal length
USEFUL FOR

Students studying optics, physics enthusiasts, and anyone interested in understanding the principles of lens magnification and image formation.

Kristy92
Messages
1
Reaction score
0
A magnifying glass has a diverging lens with a 13.0 cm focal length. At what distance from a toothpick should you hold this lens to form an image with a magnification of +5.00?

I simply have no idea what to do. I tied moving around the equations to make them work, but I can't figure it out.

Please help & thank you!
 
Physics news on Phys.org
Hi Kristy, Welcome to Physics Forums!you should have tried a bit more.

magnification = v/u = +5.

also, 1/f = 1/v - 1/u. f = -13cm for diverging lens.

solve.
 

Similar threads

  • · Replies 7 ·
Replies
7
Views
2K
  • · Replies 2 ·
Replies
2
Views
1K
  • · Replies 1 ·
Replies
1
Views
3K
  • · Replies 3 ·
Replies
3
Views
1K
  • · Replies 4 ·
Replies
4
Views
2K
  • · Replies 1 ·
Replies
1
Views
3K
  • · Replies 4 ·
Replies
4
Views
4K
  • · Replies 12 ·
Replies
12
Views
3K
  • · Replies 4 ·
Replies
4
Views
2K
Replies
1
Views
5K