# Ray Optics: Reflection and Mirrors

## Reflection and Mirrors: Audio Guided Solution

#### Problem 9:

In a physics demonstration, a concave mirror having a 50.0 cm focal length is used to create images of a candle located at various locations along its principal axis. Beginning from a distance of several meters from the mirror, a candle is moved forward and its image is projected onto an opaque screen. Determine the image distances (distance from mirror to image) for object distances (distance from object to mirror) of …
a. … 125.0 cm
b. … 100.0 cm
c. … 75.0 cm
d. … 50.0 cm (Be careful with your math; the result is surprising.)
e. … 25.0 cm

## Audio Guided Solution

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## Habits of an Effective Problem Solver

• Read the problem carefully and develop a mental picture of the physical situation. If necessary, sketch a simple diagram of the physical situation to help you visualize it.
• Identify the known and unknown quantities in an organized manner. Equate given values to the symbols used to represent the corresponding quantity - e.g., do = 24.2 cm; di= 16.8 cm; f = ???.
• Use physics formulas and conceptual reasoning to plot a strategy for solving for the unknown quantity.
• Identify the appropriate formula(s) to use.
• Perform substitutions and algebraic manipulations in order to solve for the unknown quantity.