3. TopicSlidesMinutes 1 Displacement 927 2 Vectors 1339 3 Kinematics 1339 4 Graphs 1030 5 Energy 1030 6 Power 515 7 Springs 412 8 39 9 Field of Vision 721 10 Colors 39 11 Concave mirrors 721 12 Convex mirrors 412 13 Refraction 515 14 Lenses 1030 15 Optical Power 618 Shadows

4. SHADOWS Shadows are formed when light is obstructed. The light may be totally obstructed thereby forming a dark shadow known as an umbra, or it may be partially obstructed thereby forming a gray shadow known as a penumbra. Click Penumbra (grey) Umbra (black)

7. Umbra Penumbra Click + + A) B) C) D) Shadows Slide:

8. Penumbra Click Shadows Slide:

9. When the moon’s penumbral shadow strikes the Earth, a partial eclipse is produced. In which region/s can a partial eclipse of the sun be seen? A) Region X only B) Region Y only C) Regions X and Z D) Regions X, Y and Z Click Shadows Slide:

10. … and good luck!