Fig Reflection of an object (y) from a plane mirror. Lateral magnification m = y ’ / y © 2003 J. F. Becker San Jose State University Physics 52 Heat and Optics

SIGN RULES FOR ALL REFLECTION AND REFRACTION SITUATIONS 1.SIGN RULE FOR THE OBJECT DISTANCE: When the object is on the same side of the reflecting or refracting surface as the incoming light, the object distance s is positive; otherwise it is negative. 2.SIGN RULE FOR THE IMAGE DISTANCE: When the image is on the same side of the reflecting or refracting surface as the outgoing light, the image distance s’ is positive; otherwise negative. 3.SIGN RULE FOR THE RADIUS OF CURVATURE OF A SPERICAL SURFACE: When the center of curvature C is on the same side as the outgoing light, C is positive; otherwise it is negative. © 2003 J. F. Becker San Jose State University Physics 52 Heat and Optics

Fig The image formed by a plane mirror is virtual, erect, and reversed. © 2003 J. F. Becker San Jose State University Physics 52 Heat and Optics

Fig Construction for finding image of a concave spherical mirror. The image is real, inverted, and magnified. (angle of incidence = angle of reflection, or  =  )  tan  ~  etc. so  = h / s,  = h / s’,  = h / R  1/s + 1/s’ = 2/R © 2003 J. F. Becker San Jose State University Physics 52 Heat and Optics

Fig A concave spherical mirror causes rays parallel to the axis to converge at the focal point F. For s = oo 1/oo + 1/s’ = 2/R and s’ = R /2 = f where f is the focal length of the mirror © 2003 J. F. Becker San Jose State University Physics 52 Heat and Optics

Fig Image position, orientation, and height formed by a concave spherical mirror. m = y ’ / y = - s ’ / s © 2003 J. F. Becker San Jose State University Physics 52 Heat and Optics