What this lesson teaches
Refraction and lens formula.
Can you finish convex lens focal length in about 35 min?
You will refraction and lens formula.
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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.