Question

names of group members:
metric measurements: how are metric units of measurement used in the laboratory?
in many biology investigations, precise measurements must be made before observations can be interpreted. for everyday measuring, we still use english units such as the inch, quart, and pound. for scientific work, and for everyday measuring in most countries, the international system of units (si) is used.
like our money system, si is a metric system. all units are based on the number 10. in the si system, it is easy to change one unit to another because all units are related to one another by a power of 10.
in this investigation, you will review si units for measuring length, liquid volume, and mass. you will also learn how to use some common laboratory equipment used for measuring.
background questions (read the entire investigation. then answer the following questions.)

1. why do scientists and other people in most countries use the metric system for measurements?

each measurement is related to each other by a power of 10 - easy to convert from 1 to another

1. why is it easy to change from one unit to another in the si system?
2. why is it difficult to convert miles to yards or feet?
3. name 3 aspects of everyday life that will change if our country (the usa) converts to si units.

materials: meter stick metric ruler small test tube
safety: handle all glassware carefully. if you break any glass, notify the teacher immediately.
procedure part a. measuring length

1. use the meter stick to measure the length, width, and height of your laboratory table or desk in meters. record your measurements to the nearest hundredth of a meter in data table 1.
2. convert the measurements from meters to centimeters and then to millimeters. record these measurements in data table 1.
3. use a metric ruler to measure the length of a small test tube and the diameter of its mouth in centimeters. record your measurements to the nearest millimeter in data table 2.
4. convert the measurements from millimeters to centimeters. record these measurements in data table 2. you can use the internet for this

data table 1: lab table measurements
dimension | m | cm | mm
length | 2.25 | 230 | 2300
width | 0.65 | 65 | 6500
height | 0.49 | 49 | 4900
data table 2: test tube measurements
dimension | cm | mm
length | | 50
diameter of mouth | | 2.30

Explanation:

Question 2

The SI system (metric system) has units related by powers of 10. So converting between units involves moving decimal places (multiplying/dividing by 10, 100, 1000, etc.), which is simple. For example, 1 meter = 100 centimeters = 1000 millimeters, so converting meters to centimeters is multiplying by 100, which is easy.

Miles, yards, and feet are part of the English system. Their conversion factors are not powers of 10 (1 mile = 1760 yards, 1 yard = 3 feet). These non - base - 10 conversion factors make calculations (like converting miles to yards or feet) more complex as they involve multiplying or dividing by these non - 10, non - 100, etc. numbers.

1. Driving: Road signs would show distances in kilometers instead of miles. Speedometers would be in kilometers per hour (km/h) instead of miles per hour (mph).
2. Cooking: Recipes would use metric units like grams (g) for mass and liters (L) for volume instead of ounces, cups, etc. For example, a recipe might call for 250 grams of flour instead of 1 cup.
3. Construction: Building materials (like lumber) would be measured in meters, centimeters, etc. instead of feet and inches. A 2 - by - 4 piece of lumber would have dimensions in metric units.

Answer:

Because all units in the SI system are related to one another by a power of 10, so converting between units only requires multiplying or dividing by powers of 10 (e.g., moving decimal places), making it easy.

Question 3