Lab O2 Analysis

Lab O-2: Refraction and Thin Lenses Analysis 1. Convex f = 12.40 + 12.40 2 = 12.40 cm Concave f = − 10.80 +(− 12.00 ) 2 =− 11.4 cm f avg = | 12.40 | + | − 11.4 | 2 = 11.9 cm 2. f mirror = 6.30 + 6.20 2 = 6.25 cm R = 2 f mirror = 2 ( 6.25 ) = 12.5 cm 3. 1 f avg =( n l − 1 )( 1 R 1 − 1 R 2 ) 1 − 11.90 =( n l − 1 )( 1 12.5 − ( − 1 12.5 ) ) 1 11.90 =( n l − 1 )( 2 12.5 ) n l − 1 = ( 1 11.90 )( 12.5 2 ) n l = 1 + ( 1 11.90 )( 12.5 2 ) n l = 1.53 4. d avg = 2.30 + 2.40 2 = 2.35 cm

t avg = 3.85 + 3.80 2 = 3.825 = 3.83 cm n = t avg d avg = 3.83 2.35 = 1.63 Questions 1. a. When combining the concave and convex lenses, it was seen that the light did not refract, rather they continued to go straight like they were before entering the lens. Since the radius of the convex lens, R 2 , is equal to the radius of the radius of the concave lens, R 1 , the light is not refracted. And since the light continued in a straight line like it was before entering the lenses, it shows that the focal points of the two lenses have the same absolute values, but opposite signs. b. The focal lengths for the concave and convex lenses were similar, but not the same when measured by my partner and myself. In fact, my partner had closer measurements of the focal lengths (concave = 12.00cm, convex = 12.40cm) than I did (concave = 10.80cm, convex = 12.40cm). This difference could be caused by one of us improperly tracing the lines, or making a mistake in the actual measurement. However, considering the radii of the convex and concave lenses are the same, but inverted, this should mean that the focal points of the convex and concave lenses should be the same value, with the measurement for the convex lens being positive and the concave lens being negative. This would mean my partner’s measurement is more