Chapter 13 – Light and Reflection
1) The highest directly measured frequency is 5.20 1014 Hz, corresponding to one of the transitions in iodine-127. How many wavelengths of electromagnetic waves with this frequency could fit across a dot on a book page? Assume the dot is 2.00 104 m in diameter.
2) A typical compact disc stores information in tiny pits on the disc’s surface. A typical pit size is 1.2 m. What is the frequency of electromagnetic waves that have a wavelength equal to the typical CD pit size?
3) In Alaska, the top of MountMcKinley has been seen from the top of Mount Sanford, a distance of 370 km. An object is 370 km from a giant concave mirror. If the focal length of the mirror is 250 km what are the object distance and the magnification?
4) A mature blue whale may have a length of 28.0 m. How far from a concave mirror with a focal length of 30.0 m must a 7.00-m-long baby blue whale be placed to get a real image the size of a mature blue whale?
5) In 1950 in Seattle, Washington, there was a Christmas tree 67.4 m tall. How far from a concave mirror having a radius of curvature equal to 12.0 m must a person 1.69 m tall stand to form a virtual image equal to the height of the tree? Will the image be upright or inverted?
6) The radius of Earth is 6.40 103 km. The moon is about 3.84 105 km away from Earth and has a diameter of 3475 km. The Pacific Ocean surface, which can be considered a convex mirror, forms a virtual image of the moon. What is the diameter of that image?
7) Among the many discoveries made with the Hubble Space Telescope are four new moons of Saturn, the largest being just about 70.0 km in diameter. Suppose this moon is covered by a highly reflective coating, thus forming a spherical convex mirror. Another moon happens to pass by at a distance of 100 km. What is the image distance?
8) In 1995, a functioning replica of the 1936 Toyota Model AA sedan was made in Japan. The model is a mere 4.78 mm in length. Suppose an object measuring 12.8 cm is placed in front of a convex mirror with a focal length of 64.0 cm. If the size of the image is the same as the size of the model car, how far is the image from the mirror’s surface?
Chapter 14 - Refraction
1) Extra dense flint glass has one of the highest indices of refraction of any type of glass. Suppose a beam of light passes from air into a block of extra dense flint glass. If the light has an angle of incidence of 72 and an angle of refraction of 34, what is the index of refraction of the glass?
2) Someone on a glass-bottom boat shines a light through the glass into the water below. A scuba diver beneath the boat sees the light at an angle of 17 with respect to the normal. If the glass’s index of refraction is 1.5 and the water’s index of refraction is 1.33, what is the angle of incidence with which the light passes from the glass into the water? What is the angle of incidence with which the light passes from the air into the glass?
3) An arrangement of three glass blocks with indices of refraction of 1.5, 1.6, and 1.7 are sandwiched together. A beam of light enters the first block from air at an angle of 48 with respect to the normal. What is the angle of refraction after the light enters the third block?
4) The largest of seals is the elephant seal, while the smallest seal, the Galápagos fur seal, is only 1.50 m in length. Suppose you use a diverging lens with a focal length of 8.58 m to observe an elephant seal. The elephant seal’s image turns out to have the exact length of a Galápagos fur seal and forms 6.00 m in front of the lens. How far away is the elephant seal, and what is its length?
5) The ocean sunfish, Mola mola, produces up to 30 106 eggs at a time. Each egg is about 1.3 mm in diameter. How far from a magnifying glass with a focal length of 6.0 cm should an egg be placed to obtain an image 5.2 mm in size? How far is it between the image and the lens?
6) In 1994, a model car was made at a scale of 1:64. This car traveled more than 600 km in 24 h, setting a record. If this model car is placed under an opaque projector, a real image will be projected. Suppose the image on the screen has the same size as the actual, full-scale car. If the screen is 12 m from the lens, what is the focal length of the lens? Is the image upright or inverted?
7) Hummingbirds’ eggs, which have an average size of 10.0 mm, are the smallest eggs laid by any bird. Suppose an egg is placed 12.0 cm from a magnifying glass. A virtual image with a magnification of 3.0 is produced. What is the focal length of the lens?
8) Estimates show that the largest dinosaurs were 48 m long. Suppose you take a trip back in time with a camera that has a focal length of 110 mm. Coming across a specimen of the largest dinosaur, you take its picture, but to be safe and inconspicuous you take it from a distance of 120 m. What length will the image have on the film?
9) Light moves from glass into a substance of unknown refraction index. If the critical angle for the glass is 46 and the index of refraction for the glass is 1.5, what is the index of refraction of the other substance?
10) In 1996, the Fiberoptic Link Around the Globe (FLAG) was started. It initially involves placing a
27,000 km fiber optic cable at the bottom of the Mediterranean Sea and the Indian Ocean. Suppose the index of refraction of this fiber is 1.56 and the index of refraction of sea water 1.36, what is critical angle for internal reflection in the fiber?