- What is the size of an image in a convex mirror compared to the size of the object itself?
- If you double the radius of curvature of a spherical mirror, how does its focal length change?
 What is the size of an image in a concave mirror compared to the size of the object itself?
 Suppose that a reading lamp holds a 15 W light bulb 1 m above the book that lies open in your hands. You want to double the intensity of the light that falls upon the page. Which of the following will work? (Assume that all light bulbs convert the same percentage of their electric power into light.) - Double the wattage of the light bulb.
- Move the lamp until it is half as far from the book (that is, to a distance of 50 cm).
- Either a or b.
- Neither a nor b.
 The Sun emits radiant energy (visible light, ultraviolet light, x-rays, etc.) at a rate of 3.8×1026 W. The Earth is 1.5×1011 m from the Sun.
- What is the intensity of this light, in watts per square meter, at the Earth’s distance from the Sun? (State your answer to two significant figures.)
- By what factor would you divide this intensity, if you wanted to calculate the value at Pluto’s distance from the Sun? (On average, Pluto is roughly 40 times as far from the Sun as the Earth is.)
- Suppose you are on a spaceship at Pluto’s distance from the Sun. How large (in square meters) must your solar panels be, if they are to produce 1,300 W of electric power for your ship? (Assume that the panels can capture all the sunlight that strikes them and turn it into electricity.)
- A lens has a magnification of 0.75. How long would the image of a 16-cm-long pencil be through the lens?
- Harley is at an amusement park. She is 5 ft, 10 in tall. When she stands in front of a curved mirror in the funhouse, her reflection is 7 ft tall. What is the magnification of the mirror?
| | - A scanning electron microscope magnifies objects by 2,000 times. A biologist is examining an Archean cell by using this microscope. The microscope produces an image of the cell that is 5 cm long. How long is the cell?
- A pencil 7 in in length is held up to a curved mirror with a magnification of −½. How long is the image of the pencil that this mirror produces? Will the image be right-side-up or upside-down (inverted)?
- A ray of light hits a mirror at an angle of incidence of 43°. At what angle does it reflect?
- Magdalena is standing 60 cm from her bathroom mirror, looking at her reflection in it. How far away from her is her reflected image?
- A light beam reflects off a mirror at a reflection angle of 75°. What was its angle of incidence?
- At what angle does a ray of light need to hit a mirror for the angle between the incident ray and reflected ray to be a right angle?
- The drawing shows the positions of an L-shaped object and a flat mirror.
- Draw the reflected image of the object at its correct location. (Suggestion: Use the rules of locating an image with a ray diagram.)
- What is the magnification of the image?
- What is the orientation of the image?
- If a ray of light hits a mirror at a 30° angle to the glass, what will be the angle of reflection?
- A ray of light hits a mirror and is reflected. The ray comes in at a 30° angle with respect to the mirror. What is the angle between the incident ray and the reflected ray?
- An image produced by a spherical mirror is 1/3 as large as the original object and has the same orientation. What is the magnification of the mirror?
- A 1.6-m-tall woman is standing 75 cm in front of a spherical mirror that has a radius of curvature of 60 cm. If her image is 47 cm tall, what is the focal length of the mirror?
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