Concave and Convex Mirrors Lab

Purpose: We are going to find the image of objects formed in concave mirror and convex mirror.

Convex Mirror:

We place an object in front of convex mirror, we have the image smaller than the object and upright. The image is closer to the mirror relative to the object to the mirror.
We have new image gets larger when we move the object closer to convex mirror, and the new image is bigger than the image before.
We have new image gets smaller when we move the object further from convex mirror, and the new image is smaller than the image before.


We have draw the three light rays in convex mirror worksheet and locate the image. The first ray is from the top of object and parallel the optic axis, and this ray is reflected that the extension is point to the focal point of mirror. The second ray is from the top of object to center point of mirror and reflected back to center point. The third ray is from the top of image parallel to the optic axis to object for reflected ray, and connect the point of the ray that meets the mirror to the object. We find the top of image is the intersection of these three rays formed behind the mirror.

We have object height = 3.1 ± 0.05 cm.
We have object distance = 6.1 ± 0.05 cm.
We have image height = 0.6 ± 0.05 cm.
We have image distance = 1.95 ± 0.05 cm.

We have the magnification.
m = (image height)/(object height) = (0.6 cm)/(3.1 cm) = 0.194 ± 0.0164 cm.

The observations agree with my light ray sketch as the image height in sketch is smaller than the object height, so the size of image is smaller than the size of object, and the image is also upright.

Concave Mirror:

We place an object in front of concave mirror, we have the image larger than the object and upright. The image is same location to the mirror relative to the object to the mirror.
We have new image gets smaller when we move the object close to concave mirror, and the new image is smaller than the image before.
First of all, we have new image gets bigger when we move the object further from convex mirror, and the image disappear. The inverted image is formed when the object is moved further more, and the new image get smaller, and the final new image is smaller than the image before.


We have draw the light ray in concave mirror worksheet and locate the image.The first ray is from the top of object and parallel the optic axis, and this ray is reflected to the focal point of mirror. The second ray is from the top of object to focal point, and the ray is reflected parallel to the optic axis. The third ray is from the top of object to center point of mirror and reflected back to center point. We find the top of image is the intersection of these three rays formed in front of the mirror.

We have object height = 3.1 ± 0.05 cm.
We have object distance = 11.4 ± 0.05 cm.
We have image height = 1.75 ± 0.05 cm.
We have image distance = 2.4 ± 0.05 cm.

We have the magnification.
m = (image height)/(object height) = (1.75 cm)/(3.1 cm) = 0.565 ± 0.0185 cm

The observations agree with my light ray sketch as the image height in sketch is smaller than the object height when object distance is much larger than the center distance of mirror, so the size of image is smaller than the size of object, and the image is also inverted.

Conclusion:
We successfully find the image of objects formed in concave mirror and convex mirror. We successfully sketch the rays and the image of objects in the worksheet, which matches the observation of the image formed for convex and concave mirror.