🔖 Topics

  • Ideal mirrors
  • Focal length and radius of curvature
  • Object distance and image distance
  • Magnification

🎯 Objectives

  • Describe the properties of an ideal mirror
  • Calculate the properties of images formed by an ideal mirror

📋 Sequence

We will cover plane mirrors, convex mirrors, and concave mirrors. In each of the cases, we will discuss:

  • Positive / negative conventions
  • Object further out than the focal point
  • Object closer in than the focal point
  • Object at the focal point

🖥️ Animations, Simulations, Activities

📝 Practice Problems

For each of the problems below, sketch out a ray diagram of the system before doing any calculations.

  1. A rose in a vase is placed 0.250 m in front of a plane mirror. You stand 2.00 m in front of the mirror. How far are you from the image of the rose?
  2. A 1.80 cm high object is placed 20 cm in front of a concave mirror with a focal length of 5 cm. How far from the mirror is the image located? Is it in front of or behind the mirror?
  3. An object is placed in front of a concave mirror with a radius of curvature of 25 cm. A real image, twice the size of the object, is formed. What is the object distance from the mirror? Is it in front of or behind the mirror?

✅ Partial Solutions

  1. 2.25 m
  2. 6.67 cm in front of the mirror
  3. 18.8 cm in front of the mirror

📘 Connected Resources

  • Kurmi, Manesh. “Ideal Mirror Simulator.” Ideal Mirror, https://maheshkurmi.github.io/rayoptics/ideal_mirror.html, 2022.
  • Giambattista, Alan, et al. College Physics With an Integrated Approach to Forces and Kinematics. 5th ed., McGraw-Hill Education, 2020.
  • Tipler, Paul A., and Gene Mosca. Physics for Scientists and Engineers: With Modern Physics. 6th ed., W. H. Freeman, 2008.