Experiment 7: Mirrors and Lenses

Part A: Concave Mirror

Arrangement	Object Distance (cm)	Image Distance cm)	Object Height (cm)	Image Height (cm)	Image Orientation
Projected back to object distance	7.8 cm	7.8	0	0	Upside down
Projected back to 2x object distance	15.6	11.1	0	0	Upside down(flipped)

Part B : Converging Lens

Arrangement	Object Distance (cm)	Image Distance cm)	Object Height (cm)	Image Height (cm)	Image Orientation
Image and object distance - the same	28.7	33.3	0	0	Upside down
Object at 2x image distance	66.6	22.4	0	0	Upside down
Reformed image after moving lens toward the object	20.1	68.9	0	0	Upside down (larger)
Distance object		18.1	0	0	Upside down

Part C: Diverging Lens

Arrangement	Focal Length
Diverging lens between converging lens and screen, image reflected off a mirror onto the plane of the object	74 - 50 = 24

CALCULATION AND ANALYSIS 1. Calculate the focal length of the concave mirror twice, using the data from the two rows of the data table for part A. 2. Calculate the magnification of the concave mirror for each object distance analyzed. 3. Calculate the focal length of the converging lens three times, using the data from the first three rows of the data table for part B. 4. Use the image distance for a distant object as the accepted value for the focal length of a converging lens. Calculate the % error for the focal lengths you obtained in step 3. 5. Report the focal length of the diverging lens.

parallel to the axis. For ifffors and lenses the equation relating these distances is given by equation 7.1. Mirror and Lens Equation (7.1) The sign of fis specific to each type of mirror or lens. For concave mirrors and converging lenses, f is positive. For convex mirrors and diverging lenses, fis negative. An image is said to be inverted if its orientation is opposite to that of the object. Otherwise it is said to be upright. The magnification of the image is given by equation 7.2. Magnification hi di m = (7.2) ho do Real images actually have light passing through them focused by the mirror or lens form the source