1. List the parts of the visible spectrum. Rank them by frequency, wavelength, and energy.
Red, orange, yellow, green, blue, violet At the left of the list, red is the longest wavelength with the lowest frequency and the lowest energy. Violet has the shortest wavelength, the highest frequency and the highest energy.
2. List the parts of the invisible spectrum. Rank them by frequency, wavelength, and energy.
Radio waves, microwaves, infrared, visible, ultraviolet, x- ray, gamma rays. Radio waves have the longest wavelengths with the lowest frequency and the lowest energy. Gamma rays have the shortest wavelength, the highest frequency and the highest energy.
3. If the frequency of light is 5.4 x 10 14 Hz, what is its wavelength?
c = fλ 3 x 10 8 = 5.4 x 10 14 λ λ = 5.56 x 10 -7
4. If the wavelength of light is 630 nanometers, what is the frequency?
c = fλ 3 x 10 8 = f 630 x 10 -9 f = 4.76 x 10 14
5. How does the wavelength of the light affect the speed of light in a vacuum?
9. A concave mirror has a focal length of 12 cm. If an object is placed 18 cm from the mirror, where is the image formed? What is the image’s type and orientation? What is the magnification? If the image is 2 cm tall, how big is the image? Draw a ray diagram of this situation.
1/f = 1/d o + 1/d i 1/12 = 1/18 + 1/d i d i = 36 cm real, inverted, larger M = d i /d o M = 36/18 = -2 h i /h o = d i /d o h i /2 = 36/18 h i = 4 cm
A parallel ray is reflected through the focal point.
A ray through the focal point is reflected parallel. Where they cross is the image.
10. A virtual image is formed 6 cm from a convex mirror with a focal length of -9 cm. What is the object’s distance from the mirror? Draw a ray diagram of this situation.
1/f = 1/d o + 1/d i 1/-9 = 1/d o + 1/-6 d o = 18 cm
A parallel ray is reflected so that, if extended, it would pass through the focal point.
A ray that would go through the focal point is reflected parallel. Where the extended rays cross is the image location.
11. In the diagram above, describe the image formed by object A. Object B.