1. Unit 8 – Curved Mirrors

2. Unit 8 – Concave Spherical Mirror Concave spherical mirror: a mirror whose reflecting surface is a segment of the inside of a sphere. ◦ How an image appears depends upon R, the radius of curvature. ◦ Radius of curvature is the distance from C, the center of curvature.

3. Unit 8 – Concave Spherical Mirror C = center of curvature F = focal point f = focal length = ½ the radius of curvature = R/2 p = object distance q = image distance

4. Unit 8 – Concave Spherical Mirror Image location can be predicted with the mirror equation:

5. Unit 8 – Concave Spherical Mirror Example: When an object is placed 30.0 cm in front of a concave mirror, a real image is formed 60.0cm from the mirror’s surface. Find the focal length. (20 cm)

6. Unit 8 – Concave Spherical Mirror For a concave mirror, the type of image formed depends on the position of the object

7. Unit 8 – Concave Spherical Mirror Rules for ray diagrams: RayLine drawn from object to mirror Line drawn from mirror to image after reflection 1Parallel to principal axis Through focal point F 2 Parallel to principal axis 3Through center of curvature C Back along itself through C

8. Unit 8 – Concave Spherical Mirror

11. 1) Is the image on the SAME or OPPOSITE side of the mirror as the object? ◦ Same, therefore it is a REAL IMAGE. 2) Is the image ENLARGED or REDUCED? 3) Is the image INVERTED or RIGHT SIDE UP?

12. Unit 8 – Concave Spherical Mirror

13. When the object is at infinity:

14. Unit 8 – Concave Spherical Mirror When the object is between infinity and center of curvature:

15. Unit 8 – Concave Spherical Mirror When the object is at center of curvature:

16. Unit 8 – Concave Spherical Mirror When the object is between center of curvature and focal point:

17. Unit 8 – Concave Spherical Mirror When the object is at focal point:

18. Unit 8 – Concave Spherical Mirror When the object is between focal point and mirror:

19. Unit 8 – Concave Spherical Mirror Magnification relates image and object sizes

20. Unit 8 – Concave Spherical Mirror Example: A concave spherical mirror has a focal length of 10.0 cm. Locate the image of a pencil that is placed upright 30.0 cm from the mirror. Find the magnification of the image. Draw a ray diagram to confirm your answer. (q = 15 cm, M = -0.50)

21. Unit 8 – Concave Spherical Mirror Homework: ◦ Worksheet: Concave Mirrors