Scientific Methods Lab

PART 1: Scientific Notation

A. 9.3 x 10^12

B. 7.7792 x 10^11

C. 6.1134 x 10^23

PART 2: Measurement Errors and Uncertainties

A. ----------

1) Blue: 420 nm, Yellow: 580 nm, Red: 650 nm

2) 0-20 nm off... not very accurate at all. All estimates with just eyeballing and no actual measuring.

3) By measuring the specific distances and how they relate to the 100nm markers.

4) Yellow/Blue: 2.5 cm +/- .05 cm | Yellow/Red: 1.8 cm, +/- 0.05 cm | Blue/Red: 5.3 cm, +/- 0.05 cm

5) Average: 0.426 scale factor (nm/mm)

6) Yes- they estimated their distances differently and used (possibly) different units, giving results that are mostly different.

C. ----------

Accurate: Like getting a bull's-eye. Right on target measurements, etc.. like a result being close or right on to the "pre-measured" and official result.

Precise: Getting the same sort of answer every time, but not neccessarily right on the official result. Consistent.

Galaxy Measurements, etc.

1. I used the thinnest part of the galaxy as the criteria for determining the diameter.

2. ------

a) Yes- if one measures the width one then the height for another galaxy, the sizes won't be similar and the supposed distance won't be able to be calculated.

b) No- as long as they were consistent and that eventual results were similar, it shouldn't matter, unless the galaxies aren't similar in shape.

3. I used a piece of paper and made marks on it then compared those measured marks to the other marks and determined the relative sizes/distances of the galaxies.

4. ------

a) Nearest: First one, Farthest: second one

b) About 6 times as far (using the criteria in the beginning)

c) One would have to assume that the original astronomer's postulate was true, and the photographs were taken from the same place/time on earth with the same amount of zoom on the telescope, etc.

Graphing Star Magnitude

1. I used my calculator to do this (I just took precalc so I know how to do it. : D)

2. y = -2.63x+5.6 (best fit line on calculator.. didn't hand calculate it)

3. -----

a) -2.63 = m

b) Yes. I use it a lot.

c) Yes, that makes sense.

PART 3: Significant Digits

A. ----

1) 2 sig figs

2) 5 sig figs

3) 1 sig fig

4) 3 sig figs

B. 78,801,312... 1 sig fig (from 4,000)... 8x10^4 or 80,000.