# Ray Optics: Reflection and Mirrors

## Reflection and Mirrors: Audio Guided Solution

#### Problem 18:

Kerry Uss is studying the convex side of her soup spoon. She notices that her 3.8-cm tall nose appears to be 1.2 cm tall when positioned a distance of 2.4 cm from the spoon.
a. Determine the image distance for this particular object distance.
b. Determine the focal length of the convex side of the spoon.

## Audio Guided Solution

Click to show or hide the answer!

## 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.