Examples for subject

Example #1

Problem:

a.) An image is located at exactly the same position as an object for a mirror of focal length 6 cm. What is the object distance?

Solution:

Use the formula with d_i and equal to get

d_o = 12 cm

b.) If the height of the object is 4.5 mm, what is the height of the image?

Solution:

Use to see that the image height equals the object height.

h_i = - 4.5 mm (inverted)

Example #2

Problem:

a.) A convex mirror has an object 14 cm from the mirror, and the image appears to be 7 cm behind the mirror. What is the focal length of the mirror?

Solution:

Use the formula with the image distance negative.

f = -14 cm

b.) If the object height is 8.0 mm, what is the height of the image?

Solution:

Use the formula with the image distance negative.

h_i = 4.0 cm (upright)

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