In an optics experiment, a candle is placed various distances (x, in cm)
from a lens. An inverted image of the candle flame is found on the other
side of the lens at a distance (y, in cm) from the lens.
The uncertainty in y varies quite a bit: large when y
is large and small when y
is small; the estimate for δy is given in the data table.
The lens equation predicts:
1/x + 1/y = 1/f
where f is a constant called the focal length of the lens.
The lens equation can be put in standard form:
1/y = A + B/x
where: B=-1 and A=1/f
- Fit this data to an inverse x & y relationship
- Consider the prediction of the lens equation.
Does this evidence (data) confirm or contradict this scientific claim? Support
your answer quantitatively.
- Properly report (sigfigs, error, units) the B
parameter of the best-fit function.
- Fit this data to an inverse x & y relationship with B held fixed at -1
- Properly report (sigfigs, error, units) the A
parameter of this best-fit function.
- Use a spreadsheet to calculate the focal length of the lens from A, and properly report
(sigfigs, error, units) the value.
- Self-document the spreadsheet and turn in a hardcopy of the page.
- Make a hardcopy plot of the data with best-fit curve. Make an additional hardcopy plot
with scales chosen so as to linearize the curve.
X
(cm) | Y
(cm) | δY
(cm)
|
|---|
| 18 | 88 | 15
|
| 20 | 60 | 6
|
| 22 | 50 | 3
|
| 26 | 35.5 | 1.5
|
| 30 | 30.5 | 1
|
| 40 | 24.5 | 0.5
|
| 50 | 21.0 | 0.3
|
| 60 | 20.1 | 0.2
|
| 75 | 19.0 | 0.15
|
| 90 | 17.9 | 0.1
|