posted by Anonymous on .
An object that is 27 cm in front of a convex mirror has an image located 18 cm behind the mirror. How far behind the mirror is the image located when the object is 19 cm in front of the mirror?
Compute the focal length (f) from the object and image information provided.
Then use that f (which will be negative for a convex mirror) to compute the new image position when the object is moved.
1/27 - 1/18 = 1/f
2/54 - 3/54 = -1/54 = 1/f
f = -54 cm
1/19 + 1/Di = -1/54
1/Di = -1/54 - 1/19 = -0.007115
Di = -14.05 cm
which means 14.05 cm behind the mirror
An object that is 29 cm in front of a convex mirror has an image located 13 cm behind the mirror. How far behind the mirror is the image located wen the object is 15 cm in front of the mirror?