- #1
Barclay
- 208
- 1
Homework Statement
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A student wants to find the refractive index of a rectangular block of glass. He draws around the block and marks the position of a ray of light that travels through the block. With the block removed, the student can draw in a normal line and then measure the angle of incidence and the angle of refraction. The student repeats this process for different angles of incidence. His measurements are shown in the table.
Angle of incidence Angle of refraction
10° ...... 6.5°
20° ........ 13°
30° .......20°
40° ....... 25°
50° .......32°
60° ........35°
Homework Equations
Snells law
Refractive index = (sin i / sin r)
3. QUESTIONS & the attempt at a solution
(i) Draw a diagram to show the measurements the student needs to make.
I'm okay with this part
(ii) What was the independent variable in this investigation? What was the dependent variable?
Independent variable is the angle of incidence (because it is the one that can be varied).
Dependent variable is the angle of refraction (because it is dependent on the angle of incidence).
(iii) What, if any, safety precautions should be taken if this experiment is carried out in the classroom?
Ensure that the room is dark for there is no stray light that might make the ray of light difficult to see.
(iv) Describe two possible reasons the measurements may not be completely accurate.
The beams of light may be too thick and splayed so measurements of angles will be inaccurate.
(v) What difference would it make to the results if light of a different color was used in the experiment?
The wavelength will be different so the angle of refraction will be different.
What formula links the angle of refraction and the wavelength?Thanks