Identify the meaning and sign conventions associated with focal length, radius of curvature, image height, image distance, and magnification.
The symbols in the mirror equation and magnification equation represent quantities that can take on positive or negative numerical values. For our purposes, the object height (ho) and object distance (do) are always positive. The other quantities can be + or – depending on various characteristics of the image and the mirror.
A negative image distance (di) indicates that the image is …
A negative image height (hi) indicates that the image is …
A negative focal length (f) indicates that the mirror is …
A negative magnification (M) indicates that the image is …
Consider the scaled diagram of a concave mirror with an object and image position shown. The focal point (F), center of curvature (C), object (o), and image (i) are marked on the diagram. Using the scale that each square is 6 cm along its edge, determine the …
… object distance (in cm).
Object Distance
cm
… object height (in cm).
Object Height
… focal length (in cm). Enter answer with the appropriate +/- sign.
Focal Length
… radius of curvature (in cm). Enter answer with the appropriate +/- sign.
Radius of Curvature
… image distance (in cm). Enter answer with the appropriate +/- sign.
Image Distance
… image height (in cm). Enter answer with the appropriate +/- sign.
Image Height
Consider the scaled diagram of a convex mirror with an object and image position shown. The focal point (F), center of curvature (C), object (o), and image (i) are marked on the diagram. Using the scale that each square is 8.0 cm along its edge, determine the …
A spherical concave mirror has a radius of curvature of +70 cm. What is the focal length of the mirror?
Determine the radius of curvature of a concave mirror that has a focal length of 13.0 cm.
A decorative garden sphere has a diameter of 41.6 cm. The reflecting surface of the shiny sphere makes a great convex mirror. What is the focal length of the convex surface? (Include a – sign if appropriate.)
Jaylin and Mariah are inside the Funhouse Mirror Room at the 4-H Fair. Mariah, who is 1.37 m tall, stands in front of a convex mirror. The mirror produces an image of Mariah with a magnification of +0.336. What is the height of the image?
m
It was a sunny day in May and Mrs. Burton was driving home from school with a large concave mirror on the floor behind the driver's seat. She was unaware that Physics was happening in her back seat until the driver in the adjacent lane indicated that there was lots of smoke coming out the window. It ends up that light from this object called the Sun, located 1.5x1011 m from the mirror surface, was forming an image of the sun on a sheet of paper located 54.8 cm from the mirror surface. After Mrs. Burton put out the smoldering paper, she pulled out her calculator to determine the focal length of the mirror. What value (in cm) does she calculate for focal length? (HINT: Mrs. Burton never misses a calculation.)