Name:______Period:______Date:______
Mirrors
On graph paper, please draw the following mirror diagram for question 1-5. All rays must be labeled as incident or reflected, and you must identify if the image is real or virtual; upright or inverted; reduced or enlarged. Please include all calculations to justify the predictions of your mirror diagrams.
1. A convex mirror has a radius of curvature of 30 centimeters. An object of height 7 cm is placed is placed 8 centimeters from its surface. Find the image distance, image height and magnification.
di = -5.22 cm, hi = 4.55 cm, M = 0.65, virtual, upright, reduced
2. A concave mirror has a focal length of 20 centimeters. If an object of height 12 cm is placed 30 centimeters from its surface, find the image distance, image height and magnification.
di = 60 cm, hi = -24 cm, M = -2, real, inverted, magnified
3. An object of 5 cm height is placed 8 cm from the surface of a concave mirror with a center of curative of 26 centimeters, find the image distance, image height and magnification.
di = -20.8 cm, hi = 13 cm, M = 2.6, virtual, upright, enlarged
4. The image of a concave mirror is seen +6 cm distance with a height of -3 cm from the surface of a mirror whose object is 15 cm from the surface. Find the focal length, radius of curvature and the magnification of the image. (hint: check to see if the image is upright or inverted!)
f= 4.28 cm, C = 8.56 cm, M = -0.4, real, inverted, reduced
5. An image that is +20 cm tall has a magnification of 2 X. If the focal length of the concave mirror is 16 cm, and the object is located 8 cm from the surface, find the image distance, the center of curvature, and the object’s height.
di = -16 cm, hi = 32 cm, M = 0.65, virtual, upright, enlarged
6. A convex mirror has a focal length of 10 cm, with an object of 6 cm from its surface. If the object height is 8 cm, find the image distance, the image height and magnification.
di = -3.75 cm, hi = 5 cm, C =32 cm, virtual, upright, reduced
di
7. Using the mirror equation, explain why the image distance and the object distance are equal for a flat mirror. Because the focal length of a planar mirror is ¥, the mirror equation becomes
1∞ = 1do +1di. 1∞ equals 0, so the equation breaks down to do = -di
8. Identify which portions of the spectrum (give me wavelengths, frequencies) are used in each of the following devices, then rank them from lowest to highest energy:
a. a microwave oven 10-4 to 0.1 m
b. x-ray technology 10-11 to 10-9 m
c. night-vision goggles10-6.5 to 10-4 m
d. tanning beds. 10-9 to 10-6.5 m
9. Describe the difference between specular reflection and diffuse reflection and give TWO examples of each type of reflection. Specular diffusion occurs when light rays reflect parallel to each other to produce a clear shiny, such as a mirror or a smooth reflection on a pond. A diffuse reflection occurs when light rays reflect at different angles, causing a matt type surface, such as a paper bag or a burlap sack.
10. Why do the images produced by two opposing flat mirrors appear to be progressively smaller?
Because images serve as objects for more images. Each reflection doubles the apparent distance from "object" to mirror