scientific units & conversions...basic s.i. units • s.i. units: units of measurement that all...

Scientific Units & Conversions

Objective: Students will be able to convert units and choose appropriate units of measurement.

Basic S.I. Units

• S.I. Units: Units of measurement that all scientist across the world agree to use.

• Normally they use the metric system, but there are some exceptions (i.e. Temperature is Celsius in the metric system but is Kelvin in S.I. units.

Students will be able to convert units and chose appropriate units of measurement.

I will be able to use dimensional analysis to convert a metric unit.

Basic S.I. Units• Important Metric Prefixes



Measurement Unit Abbreviation of Unit

Length

Mass

Time

Weight / Force

Speed

Metric Prefixes• Important Metric Prefixes



Prefix Prefix Abbreviation. Conversion Rate

Kilo- = 1 Base Unit (like a meter)Centi- = 1 Base UnitMilli- = 1 Base Unit

Dimensional Analysis

• Dimensional Analysis: A way to convert units by using fractions that represent the conversion ratios.

• Steps for Dimensional Analsys:1. Write the original Value as a Fraction

2. Create a new fraction beside the original, place the units on the new fraction to cancel out the original unit.

3. Place the conversion numbers beside the matching unit.

4. Repeat steps 2 and 3 until you have converted to the appropriate unit.



Dimensional Analysis Practice

• Sometimes you may have to convert more than one unit at a time. Still follow the same steps.

• Example: Turning Km/H to m/s.




Example 1: Convert 86.5 grams to kilograms.




Example 2: Convert 9.8 cm to m.




Example 3: Convert 45 km/h to m/s




Example 4: Convert 1,000,000 seconds into a years.



Scientific Notation• Scientific Notation: A way to write a number using powers of ten.

Steps to Writing Scientific Notation.1. Create the digit by moving the decimal to create a number that is BEWTEEN 1

and 10.

2. Multiply by 10.

3. Count the number of places the decimal has moved, a create the exponent for 10.

4. Moved Left = Positive, Moved Right = Negative.



Scientific NotationChanging Sci. Not. back to Standard Notation

1. If the exponent is “+”, move the decimal right (make the number bigger), if “ - ” move the decimal left.



Scientific Notation with a Calculator

• Example: 2.99 x 10 8 will look like ( 2.99 E 8 ) on the calculator.

• Type: ( 2.99 ) ( 2nd ) (x-1 ) ( 8 )

Scientific Notation Examples

• Example 1:

Write the mass of the Earth in Scientific Notation.

5,973,600,000,000,000,000,000,000 kg




• Example 2:

• Write the diameter of a carbon-12 atom in scientific notation.

• 0.0000000000000000000000299 mm




• Example 3:

The mass of a proton is only 1.66 × 10-27 kg. Write this number in standard form.




• Example 4:

• The distance from the Earth to the Sun is 1.49 x 1011 meters. Using dimensional analysis, convert this value to kilometers and write it in Standard Notation.



Identifying Parts of an Experiment

• AVID Experiment Vocabulary Note Sheet.

• Guide to Creating an Experiment Note sheet.



scientific units & conversions...basic s.i. units • s.i. units: units of measurement that all...

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