Concave and Convex Mirrors Lab

Objective: observe and analyze the images formed by concave and convex spherical mirrors.

Lab Equipment:

- Convex Mirror
- Concave Mirror
- Object (bag of oats)
- Ruler
- Worksheets (substituted whiteboard diagram for ray diagram worksheet)

Lab Procedure:

1) place an object in front of a convex mirror and describe the image characteristics specified in the lab manual.
2) Repeat this process for an object placed in front of a concave mirror.
3) Complete the ray diagrams as instructed in the lab manual.

Observations:

Convex Mirror

a) the image appears smaller than the original object

b) the image is upright in comparison to the original object

c) the image is located somewhere behind the convex mirror

2) When the object is moved closer to the mirror the image appears to approach the object's actual size.

All other aspects of the image remain the same as stated above.

3) When the object is moved further away from the mirror the image appears to shrink in comparison to the object's actual size. All other aspects of the image remain the same.

Convex Mirror Ray Diagram

1) Draw a ray parallel to the optic axis to the mirror. The reflected ray will go in the opposite direction of the focal point.

2) Draw a ray from the object to the center of curvature of the mirror. The reflected ray will go in the opposite direction of the original ray.

3) Draw a ray from the object to the mirror in the direction of the focal point of the mirror. The reflected ray will be parallel to the optic axis.

Measurements: do = 15 cm, ho = 10 cm, di = -7 cm, hi = 5 cm

All of our observations agree with the light ray sketch.

Concave Mirror

(original observations taken at about focal length)

a) The image appears larger than the object.

b) The image appears upright in comparison to the original object.

c) The image is located in front of the mirror.

2) When the object is moved closer to the mirror the image appears to be the same size as the object and the image is located behind the mirror. The image remains upright.

3) When the object is moved further away from the mirror, the image is inverted and becomes much smaller than the original object. The image is located in front of the mirror.

Concave Mirror Ray Diagram

1) Draw a ray from the object parallel to the optic axis. This ray will reflect from the mirror toward the focal point.

2) Draw a ray from the object through the focal point. This ray will reflect from the mirror parallel to the optic axis.

3) Draw a ray from the object through the center of curvature. This ray will reflect   back in the opposite direction from which it came.

Measurements: do = 20 cm, ho = 8 cm, di = 12 cm, hi = -5 cm

our observations do agree with our light ray sketch for objects placed relatively far away from the mirror (more than a focal length).