What this lesson teaches
Refraction and lens formula.
Find focal length of a convex lens using distant object!
Sign in to start the full activity flow, save this lesson, print a learner version, and track XP. The preview below is public so parents and educators can evaluate the activity before joining.
Refraction and lens formula.
Finding the focal point of a physical lens through direct observation makes the concept of focal length personally anchored rather than textbook-defined. Students who locate a focal point themselves can apply the concept to eyeglasses, cameras, and telescopes without being told — they already know what focal length means.
1. Set up lens between candle and screen. 2. Adjust for sharp image. 3. Measure distances. 4. Calculate f.