Scientific Methods Answer Sheet
- Scientific Notation
- Multiply: 3.1 x 107 by 3 x 105
- Multiply: 1.496 x 1011 by 5.2
- Divide: (6.4 x 106)2 by 6.7 x 10-11
- Measurement Errors and Uncertainties
A. Measurement Errors
- What is the uncertainty in your answer? That is,
how far off (in nm) could your determinations be?
- How could you make your answer more precise?
- Blue and yellow:
yellow and red:
blue and red:
- Scale Factor:
- If you had a friend measure the distances,
would her/his results differ from yours? Why or why not?
B. How does an "accurate" measurement differ from a "precise" measurement?
C. Diameters of galaxies:
- What criteria did you use when determining each diameter?
- In determining the relative distances of these galaxies:
- Would it matter if you used a different criterion
for measuring each galaxy? Why or why not?
- Would it matter if one of your class mates used different criteria
than you did? Why or why not?
- Which galaxy is the nearest? Farthest?
- How much farther away from us is the farthest galaxy compared
to the nearest?
- What assumption (stated above) is necessary for you to feel
confident your answer is correct?
- Using a piece of graph paper, plot the magnitude (brightness) of the
star against its size.
- What is the slope of the line?
- Does the equation, y = mx + b seem familiar?
- Do you see that for all future measurements, all we need to
do is measure the size of the star and use our relationship to
find the corresponding magnitude?
- Significant Digits
- How many significant digits are in the following numbers?
- Multiply 1.5, 3.5689, 4000, and 3.68. Round your answer
to the correct number of significant digits.