Reflection and Mirrors Legacy Problem #4 Guided Solution
Problem*
Anna Litical is doing the Plane Mirror Lab in physics class. She places a pin a distance of 4.9 cm from a plane mirror. How far behind the mirror can the image be expected to appear?
Audio Guided Solution
One of the characteristics of a plane mirror image that you can always count on is that the distance from the image to the plane mirror surface is actually equal to the distance from the object to the plane mirror surface. So in this lab, Analytical is placing a pin a distance of 4.9 centimeters from the plane mirror. We wish to know how far is the image from the plane mirror. So the pin is the object and the object distance or distance from object to mirror is 4.9 centimeters. So the distance from image to mirror is also 4.9 centimeters.
Solution
4.9 cm
Habbits 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., \(\descriptive{d_o}{d_o,distance object} = 24.2\unit{cm}\); \(\descriptive{d_i}{d_i,distance image} = 16.8\unit{cm}\); \(\descriptive{f}{f,focal length} = \colorbox{gray}{Unknown}\).
- 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.
Read About It!
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