✔ 最佳答案
A: no paralla method, the major error will be the distance of focus, how do you know the sport is in focus?? there may be few mm error. if you are using noraml lens (no calibrated lens), is the objective along the optical axis ?? very hard the know that, but if you try to align, that will be 2nd error. and the 3rd error is, are your light source is monochromatic?? since each wavelength has different focal length for normal lens.
B: don't know what you are saying. may be have a diagram is better.
C: i think you are finding the refractive index of glass, not water. sicne i dun know your set up, if you use naked eyes to measure the angle, it is unacceptable! you need to look through with some kind of telescope or some tube. the error will come from what is the resolution of your telescope, or the size of your tube, this mean, what is the smallest angle you can identisfly? the 2nd one is your light source (bg light), is it monochomatic??
for all experiments, systematic error and human error should be included la,