(Solved): Part IV: Refraction 1. Draw a set of perpendicular lines on a sheet of plain white paper and place ...

Part IV: Refraction 1. Draw a set of perpendicular lines on a sheet of plain white paper and place the rectangular refraction block on these lines as shown in Fig.8. 5 2. Place a pin at point \( B \) on the normal line against the side of the refraction block. 3. Place pin \( A_{1} \) about \( 4 \mathrm{~cm} \) away from the block and to one side of the normal so that line \( A_{1} B \) will make a \( 30^{\circ} \) angle with the normal. 4. While viewing through the plastic from the other side of the block, line up the pins \( A_{1} \) and \( B \) with a third pin \( C_{1} \) against the side of the block. Fig. 8 - Refraction block set up for the air to 5. Remove the refraction block and glass case connect the points \( A_{1} B \) and \( C_{1} \) by 5. Remove the refraction block and glass case connect the points \( A_{I} B \) and \( C_{I} \) by drawing straight lines between the points. 6. Measure the angle of incidence between the normal line Fig. 9 - Raw data table for angle of incidence and and the line \( A_{1} B \) and the angle of refraction - air to glass case refraction between the normal line and the line \( B C_{1} \). Record these values in a raw data table similar to the one shown in Fig.9. 7. Repeat steps 3-6 with pin \( A_{2} \) at a \( 45^{\circ} \) angle. Label the new points as \( A_{2} \), and \( C_{2} \). 8. Calculate the index of refraction using the angle fig. 10 - Processed data table of incidence and the angle of refraction data with for index of Snell's Law noting that the index of refraction for air is \( n=1 \). Then find the average index of refraction. Record the results to a processed data table similar to the one shown in Fig. 10. Note that this is the case where light travels from air into glass. 9. Take a new piece of paper and draw a set of perpendicular lines and place the rectangular refraction block on these lines as shown in Fig.11. 10. Place a pin at point \( B \) as shown in Fig. 11 - Refraction block set up for the glass Fig.11. to air case 11. Place pin \( C_{1} \) at an arbitrary point on the opposite side of the glass against the glass. 12. View it from the side of the glass which has pin \( B \) at the normal. The light is now traveling from pin \( C_{1} \) through the glass and then through the air to your eye. In this case the angle of incidence is in the glass and the angle of refraction in the air. 13. While your eye is aligned with pin \( C_{1} \) and pin \( B \), set a third pin \( A_{1} \) about \( 4 \mathrm{~cm} \) from the block in the line of sight between the glass block and your eye. Fig. 12 - Raw data table for angle of incidence and refraction including the critical angle - glass to air 14. Remove the refraction case block and connect the points \( C_{1} B \) and \( A_{1} \) by drawing straight lines between the points. 15. Measure the angle of incidence between the normal line and the line \( C_{1} B \) and the angle of refraction between the normal line and the line \( B A_{1} \). Record these values in a raw data table similar to the one shown in Fig.12. 16. Repeat steps 11-15 with pin \( C_{2} \) at a different angle. Label the new points as \( A_{2}, C_{2} \), 17. Try moving pin \( C_{3} \) farther and farther away from the normal and see if you can find a position for pin \( C_{3} \) that would give an angle of refraction of \( 90^{\circ} \). In this case the angle of incidence is called the critical angle \( \theta_{c} \). 18. Remove the refraction block and connect the Fig. 13 - Processed data table points \( C_{3} B \) and \( A_{3} \) by drawing straight lines between for index of refraction - glass the points. In this case the line \( b \) to \( A 3 \) should be a to air case horizontal line since angle of refraction is \( 90^{\circ} \). 19. Measure the angle of incidence or the critical angle between the normal line and the line \( C_{3} B \). Record it in a raw data table similar to the one shown in Fig.13. 20. Calculate the index of refraction using the angle of incidence and angle of refraction data with Snell's Law noting that the index of refraction for air is \( n=1 \). Then find the average index of refraction. Record it to a processed data table similar to the one shown in Fig. 12. This is the case where light travels from glass into air. 21. Take the grand average for the index of refraction found in steps 8 and 20