Principle Rays – Same as in Concave Mirrors Always remember that when locating an image – ALL RAYS ORIGINATE FROM THE OBJECT!
4 Convex Mirrors Focal Point For convex mirrors: Parallel rays hitting a spherical mirror appear to come together (intersect) at the focal point Focal point, F,is behind mirror 2F = C Note: use dotted lines to represent “imaginary” light rays
5 Image Formation using Ray Diagrams for a Convex Mirror Image Properties L behind mirror O upright S smaller than object T virtual Image properties are same regardless of object location See animation
7 Image Formation using Ray Diagrams for a Convex Mirror For a convex mirror, rays from the object will diverge (i.e. spread out) upon being reflected, thereby appearing to originate behind the mirror. The image is located where the projections (dashed lines) of the three rays cross (intersect). Use dashed lines to extend rays behind mirror. The size of the image can be determined if you draw your diagram to scale.
8 Image Properties (LOST) for Concave/Convex Mirrors Concave Mirror L varies O Upright or Inverted S varies T real or virtual Image properties depends on object location Convex Mirror L behind mirror O upright S smaller than object T virtual Image properties are same regardless of object location
Complete Ray Diagrams for Different Object Locations Complete the 2 nd page of the ray diagrams worksheet.
10 TRY ONE! An object 5 cm high is placed 10cm in front of a convex mirror with a focal length of 20cm. Using a scale ray diagram indentify the characteristics of the image.