1090 words - 5 pages

Lab 1: Introduction

Metric System

Prefixes (to put in front of basic units):

k = kilo = 1000 x

c = centi = 1/100 of (which is 10-2 of)

m = milli = 1/1000 of (which is 10-3 of)

( = micro = 1/1,000,000 of (which is 10-6 of)

n = nano = 1/1,000,000,000 of (which is 10-9 of)

(d = deci = 1/10 of )

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(Note: The way to read the numbers above, for example, is: There are 1000 nm in one (m. There are 1000 (m in one mm.. etc.)

To convert from one metric unit to a different metric unit (a different prefix):

1. First, decide how many places to move the decimal point (the number of 0’s in the chart above indicates the number of places to move the ...view middle of the document...

For example:

2.5 m X 1000 mm = 2,500 mm

1 m

NOTE: Using conversion factors to cancel units is useful in a lot of situations, including if one has to switch from English to metric measuring systems (or vice versa).

For example, in the “Measurement Conversions” table at the front of your lab manual you see that 1 kg is the same as 2.21 pounds (lb). Thus, to convert between kg and pounds, you need to use the ratio of 1 kg/2.21 lb, or 2.21 lb/1 kg. You choose which goes in the numerator and which in the denominator depending on which units you want to cancel out. Thus:

1.3 lb x 1 kg = 1.3 kg = 0.59 kg

2.21 lb 2.21

In general:

# to be converted x conversion fraction = answer

(with original units) (# with new units)

Graphing Rules

- Check all the graphing rules described in your lab manual (pp. 15-18).

- Label the axes (don’t forget units). Each bar in a bar chart needs a label, but the “x-axis” as a whole also needs a general label that is relevant to all the bars.

- Give your graph a figure number and an informative (“stand alone”) figure caption (~ title).

- If you make a graph by hand:

- Do hand graphs in pencil so mistakes can be erased.

- If you are making a graph by hand, don’t forget to actually draw in the axes, using a ruler, and also use a ruler to draw bars neatly.

- Put “tick marks” on the axes beside each number. Remember, each interval between tick marks must be worth the same amount for a given axis.

- For hand graphs, do NOT use the grids provided in the lab manual (e.g. do NOT use the grid on p. 17 or p. 18). Instead, use the squared paper in the lab manual at the end of each unit for graphing (e.g. pp. 29-31).

- Note that your graph’s origin does not always have to start with zero, but you MUST indicate what the starting value is for any axis.

- Make a nice, large graph, if possible (but keep the axes easy to read).

Tables

- Information about constructing tables is given in your lab manual on pp. 14-15.

- Note that a summary table usually provides information about average values for each group in a column, and the number of replicates involved in another column, rather...

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