Geometric Optics, Ray Tracing, and Image Formation PRE-LAB QUESTIONS 1. An object is 15 cm away from a diverging lens. If the diverging lens creates a virtual image located 6 cim from the lens of the object, what is the lens' focal length? If the object's original height was 4 cm, what is the height of the image? Show your work. 2. A convex lens has a focal length of 10 cm. If an object is located a very large distance away from the lens, at what distance away from the lens does the image form? 3. Lassie is 66 cm in height and 68 cmn in length. She stands with her face 10 meters from the plane of the thin convex lens whose focal length is 2.5 m. What is the height and length of Lassie's image? 4. Prove that image height, h, is equal to s. h,/ s. (where h and s are the image height and position of the object and h' and s' are the height and position of the image) Hint Draw a ray diagram with the center ray. 5. What kind of mirror would you use if you needed to start a fire using a mirror? Why? At what position would you place the kindling from the mirror? 6. If you wanted to develop a telescope, what kind of lenses would you use for the objective lens (the lens that collects the light) and the eyepiece? Explain your reasoning. Draw a picture with ray tracing of your setup. DeScience Labs, 2014