Ray Diagrams for Mirrors and Lenses Before we
Ray Diagrams for Mirrors and Lenses
Before we can work with telescopes � We need to understand how they are constructed � How light travels from the star to our eyes � Understand how lenses are combined with other lenses � Understand how lenses are combined with mirrors � Use refraction and reflection
Mirrors first F = focal point C = center of curvature F mirror C object
Rules for a concave mirror diagram Any incident ray traveling parallel to the principal axis on the way to the mirror will pass through the focal point upon reflection. object F mirror C
Rules for a concave mirror diagram Any incident ray passing through the focal point on the way to the mirror will travel parallel to the principal axis upon reflection. object F mirror C Imag
Real or VIRTUAL � Plane mirrors are always virtual � Curved depend on position of object
Real or VIRTUAL � Real images are always formed on the same side of the mirror as the object. � REAL, the image of the object could be projected upon a sheet of paper. � Virtual form on the other side of the mirror � Virtual cannot be projected
L. O. S. T. ANALYSIS �We need to find ◦ L = location ◦ O – orientation (inverted or upright) ◦ S = size (magnified, reduced, same) ◦ Type (real or virtual
Rules for a concave mirror diagram • This diagram is formed when you put the ojbect BEYOND C • It produces a REAL IMAGE • This image is also SMALLER and INVERTED
Rules for a concave mirror diagram • This image is formed when you put the object AT C • It produces a REAL IMAGE • This image is also EQUAL SIZE and INVERTED
Rules for a concave mirror diagram • This image is formed when you put the object in front of F • It produces a Virtual IMAGE • This image is also Larger SIZE and Upright
Rules for a concave mirror diagram • This image is formed when you put the between F AND C • It produces a REAL IMAGE • This image is also Larger SIZE and INVERTED
Weird When the object is located at the focal point, no image is formed. light rays from the same point on the object will reflect off the mirror and neither converge nor diverge. After reflecting, the light rays are traveling parallel to each other and do not result in the formation of an image.
Can you see me?
PRACTICE PROBLEMS WORK SHEETS � We ◦ ◦ need to find L = location O – orientation (inverted or upright) S = size (magnified, reduced, same) Type (real or virtual
Practice problem 1 L IN FRONT OF MIRROR O INVERTED S SMALLER T REAL
Practice Problem 2 L IN FRONT OF MIRROR at the image O INVERTED S SAME SIZE T REAL
Practice problem 3 L IN FRONT OF MIRROR BEHIND OBJECT O INVERTED S LARGER T REAL
Number 1
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