Physics 014 Images

Topics  Plane mirrors  Spherical mirrors  Thin lenses

Plane Mirrors  A virtual image CANNOT be seen on a screen  A real image CAN be seen on a screen

Plane Mirrors

 O is a point source of light  Incident beams from O reflect off plane mirror  Beams reflect at angles consistent with law of reflection  Extend reflections to I, the virtual point image

Plane Mirrors

 For the plane mirror, i=-p  i is the image distance, p is the object distance

Plane Mirrors

 For extended objects Draw ray from base Draw several rays from tip Where ray extension from tip converge is tip image point

Spherical Mirrors  Two types of spherical mirrors  Concave mirror: light rays converge on real focus  Convex mirror: light rays diverge from virtual focus

Spherical Mirrors

 Concave mirrors:  Increase image size  Move image farther away  Reduce field of view Spherical Mirrors

 Convex mirrors:  Decrease image size  Move image closer  Increase field of view Spherical Mirrors

 We can find an expression relating the distances f, p, and i

Spherical Mirrors  How do I find the image using rays?

Spherical Mirrors

 Extend rays from tip and base of object to determine image location and orientation

Spherical Mirrors 1.Parallel ray reflected through focal point 2.Ray through focal point reflected parallel 3.Ray through center 4.Ray reflected symmetrically from c

Thin Lenses  Two types of lenses  Converging lenses cause rays to converge on focal point  Diverging lenses cause rays to diverge from focal point

Thin Lenses

 We may use the same equation we used for mirrors to relate i, p, and f This is not the lens maker’s equation!

Thin Lenses

1.Ray initially parallel converge on focal point 2.Ray initially through focal point emerges parallel 3.Ray through center emerges unchanged

Thin Lenses