Name: ____________________ Date:__________ Unit ...



METRIC SYSTEM AND MEASUREMENT

Q: What is the metric system?

A: The metric system is:

▪ A system of measurement based on ________________ (powers of 10), that measures certain basic ________________ and uses standard ________________ ________________ of measurement to measure those quantities.

▪ The ________________ system of measurement for all ________________ and throughout most of the world.

▪ Sometimes referred to as the ________________ ________________ of ________________(SI).

Q: Why do all scientists use a common system of measurement?

A: The sharing of experimental ________________ and ________________ among scientists is easier and more ________________ when everyone is using the same system of measurement.

Q: What are the basic SI quantities and how are they measured?

A: There are actually ________________ basic SI quantities, but we are only concerned with the following ________________:

1. ________________:

▪ The measure of the straight-line ________________ between any two points.

▪ Measured using ________________ ________________, rulers, tape measures, etc.

2. ________________:

▪ The measure of the amount of ________________ in an object.

▪ NOT the same as ________________ (the force of gravity on an object).

▪ Measured using ________________ and ________________.

3. ________________:

▪ The measure of the ________________ or interval between two events.

▪ Measured using ________________ and ________________.

4. ________________:

▪ The measure of the average kinetic _______________ of all the particles within an object.

▪ Measured using a ________________.

5. ________________ ________________:

▪ The measure of the rate that electric _______________ move through a _______________.

▪ Measured using an ________________.

Q: What are the units of measure and symbols of the basic SI quantities?

A: Since each basic SI quantity is measured using different lab ________________, each has a different ________________ of measure and ________________.

TABLE 1: Base Units and Symbols of the Basic SI Quantities

|QUANTITY |BASE UNIT |SYMBOL |

| | | |

| |Meter |m |

| | | |

|Mass | |g |

| | | |

|Time |Second | |

| | | |

|Temperature | |K |

| | | |

| |Ampere |A |

Q: What about other quantities we measure in science, such as volume and density? Why aren’t they considered basic SI quantities?

A: Quantities such as volume and density are actually ________________ of basic SI quantities and we use combinations of base units for their measurement called _____________ ______________.

1. ________________:

▪ Is a measure of ________________, such as the capacity of a container, or the three dimensional space something ________________.

▪ Scientists often measure volume in units of ________________ and ________________. Another common unit for volume is the cubic centimeter (cm3 or cc). ________________

▪ Volume can be measured using a graduated ________________, measuring cup or spoon, beaker, or the _____________ _____________.

▪ When measuring volume using a graduated cylinder, always read from the bottom of the ________________ (the curve of the liquid in a graduated cylinder).

2. ________________:

▪ Is the ratio of an object’s ______________ and its _____________ and is calculated by dividing the object’s mass by its volume (D=m/v).

▪ The unit of measure for density is ________________.

Q: So all metric quantities, large or small, are measured in these base units?

A: No. Consider the base unit for measuring length, the meter. It would be very difficult to measure the length of objects much ________________ or ________________ than a meter with a meter stick. Therefore, the metric system uses a set of ________________ for measurements larger and smaller than the base unit.

TABLE 2: SI Prefixes for Measurements Larger than the Base Unit

|PREFIX |SYMBOL |MEANING |MULTIPLE OF BASE UNIT |

| | | | |

| |D |ten |10 |

| | | | |

|hecto- | |hundred |100 |

| | | | |

|kilo- |K | |1000 |

| | | | |

|mega- |M |million | |

| | | | |

| |G |billion |1 000 000 000 |

TABLE 3: SI Prefixes for Measurements Smaller than the Base Unit

|PREFIX |SYMBOL |MEANING |MULTIPLE OF BASE UNIT |

| | | | |

|deci- |d |tenth | |

| | | | |

|centi- |c | |0.01 or 1/100 |

| | | | |

|milli- | |thousandth |0.001 or 1/1000 |

| | | | |

| |µ |millionth |0.000 001 or 1/1 000 000 |

| | | | |

|nano- |n | |0.000 000 001 or 1/1 000 000 000 |

|Practice Problem #1: |

|The base unit for length is the meter (m). How can we express the length of your foot in m? What about the distance from your house to Cedar Point in Ohio? |

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Q: How can we convert from one metric unit to another?

A: We use Dimensional Analysis, which is a conversion technique that uses conversion factors to convert metric units to other metric units and to other common units.

A conversion factor is a numerical factor used to multiply or divide a quantity when converting from one system of units to another.

Q: How will we know which conversion factors to use?

A: For ________________ metric to metric conversions, the conversion factors can be found in ________________ and ________________ above. Other conversion factors will be given to you in the problem if you need them (ex: 1 km = 0.62 miles) and others are common knowledge (ex: ________________). There is also a conversion chart attached to this note packet.

Q: How do we use dimensional analysis?

A: The steps of dimensional analysis are:

Step 1: Identify your ________________ unit and what unit you are converting to.

Step 2: Draw your dimensional analysis ________________.

Step 3: Write your known quantity in the ________________ ________________ space on the grid.

Step 4: Write your first conversion ________________ in the space next to your known quantity with the same unit as the known quantity on the bottom. Put another vertical ________________ on your grid after it.

Step 5: Common units found ________________ from one another on the grid can cancel out. ________________ these units out.

Step 6: Repeat steps 4 and 5 as many times as needed until you have the ________________ you need your final answer to be in.

Step 7: Complete the ________________ (multiply the ________________, multiply the ________________, then ________________ the numerator by the denominator).

Step 8: Add ________________ to your final answer.

|Practice Problem #2: |

|Convert 2 mg to g using dimensional analysis. |

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|Practice Problem #3: |

|Convert 3 kiloliters to liters using dimensional analysis. |

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|Practice Problem #4: |

|Convert 10 mm to km. |

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|Practice Problem #5: |

|Convert 347 meters to feet using dimensional analysis. 1 m = 39.37 in. |

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_________________________________________________________________________________________

SCIENTIFIC NOTATION

Q: Why is scientific notation useful when studying Physics Essentials?

A: As you will see throughout this semester, many of the concepts in Physics involve very large or very small ________________. Scientific notation makes it much easier to express these numbers and work with them in ________________. Scientific notation involves expressing values as a simple number multiplied by a power of ________________.

Example: Some scientific distances in long form and scientific notation:

Distance from Earth to Neptune = 4 600 000 000 000 m = 4.6 x 1012 m

Diameter of an electron = 0.000 000 000 001 mm = 1.0 x 10-12 m

Applying Math Skills and Using Scientific Notation

The speed of light in water is ________________ km/s. Write this number in scientific notation.

1.      Identify the known values and the unknown value.

________________ Value: The speed of light in water is 226,000 km/s

________________ Value: The number 226,000 written in scientific notation

2.    Solve the problem.

A number written in scientific notation has the form ________________. N is the number of places the ________________ ________________ in the number has to be moved so that the number M that results has only one ______________ ______________ number to the left of the decimal point.

Write the number in scientific notation: ________________

Move the decimal point so there is only one whole number to its left: ________________

The decimal point was moved 5 places, so N equals 5: ________________

Delete remaining zeroes at the end of the number: ________________

3.    Check your answer.

Add ________________ to the end of your number and move the decimal point in the ________________ direction five places. The result should be the ________________ number.

Note: When the decimal point is moved to the ________________, N will be a ________________ number. If the decimal point has to be moved to the ________________, N will be a ________________ number.

Example: 0.0000034 written in scientific notation would be ________________

|Practice Problem #6: |

|Convert 800 000 000 m to scientific notation. |

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|Practice Problem #7: |

|Convert 0.000 000 000 06 kg to scientific notation. |

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|Practice Problem #8: |

|Convert 4.5 x 103 g to long form. |

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Q: Can I do scientific notation on my calculator?

A: Yes, if you have a ________________ calculator. Calculators vary, but most have an EE or EXP key that allows you to enter the ________________. Change the sign on the exponent using the ________________ key. You can then treat the number in scientific notation as a regular calculator entry and add, subtract, multiply, and divide with it.

|Practice Problem #9: |

|Use your calculator to divide 4.6 x 1012 by 3.0 x 108. |

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_________________________________________________________________________________________

THE SCIENTIFIC METHOD AND EXPERIMENTAL DESIGN

Q: What is the scientific method?

A: The ________________ ________________ is a way to ask and answer scientific questions by making observations and doing experiments following a series of steps. Scientists use this method to search for cause and effect ________________ in nature.

Q: What are the steps of the scientific method?

A: The steps of the scientific method are:

1. ________________ a ________________:

▪ The scientific method starts when you ask a question about something that you ________________: How, What, When, Who, Which, Why, or Where?

▪ The question must be about something that can be ____________, preferably with a number.

2. Do _______________ ________________:

▪ Use the ________________ and internet to do research.

▪ Find out about ________________ attempts by other scientists to answer your question.

▪ ________________ the best way to go about answering your question.

3. ________________ a ________________:

▪ A hypothesis is an ________________ ________________ about how things work.

▪ The hypothesis should be written in the following ________________:

“If __(I do this)__, then __(this)__ will happen, because of_(reason for results)_______”

▪ It must be stated in a way that can easily be ________________ and in a way to help answer the original question.

4. ________________ the Hypothesis with an ________________:

▪ The experiment tests whether the hypothesis is ________________ or ________________.

▪ It’s important for the experiment to be a ________________ test – be sure that only one factor is changed at a time while keeping all other conditions the same. This way, scientists can see how changes to one item ________________ something else to change.

▪ The experiment should also be ________________ several times to make sure the first results weren’t just an accident.

5. ________________ the ________________ and ________________ a ________________:

▪ Once the experiment is complete, ________________the measurements and analyze them to see if the hypothesis is true or false.

▪ If the hypothesis is false, ________________ a new hypothesis and start the entire process of the scientific method over again.

▪ Even if the ________________ is true, the scientist may want to test it again in a new way.

6. ________________ the ________________:

▪ Professional scientists do this by ________________ their final reports in a scientific journal or presenting their results at a scientific meeting.

Note: Even though this process is shown as a series of ________________, new information or thinking may cause a scientist to back-up and ________________ steps at any point during the process.

Q: How is a scientific experiment designed?

A: A scientific experiment consists of ________________ parts:

1. ________________ ________________:

▪ The parts of the experiment that ________________.

▪ Also called ________________.

▪ A good experiment tests the effect of only ________________ variable at a time.

▪ There are two types of variables in an experiment:

a) ________________ Variable:

• The variable that is ________________ by the scientist.

• Can be determined by asking yourself, “What am I ________________ in this experiment to produce a ________________?”

b) ________________ Variable:

• The variable that changes ________________ of the change in the independent variable.

• Can be determined by asking yourself, “What am I ________________ as I change the independent variable?”

2. ________________ ________________:

▪ The parts of the experiment that will stay the ________________.

▪ You may have ________________ control factors in one experiment.

▪ Can be determined by ________________ yourself, “What am I keeping the same in this experiment?”

▪ One group will also be known as the control group.

▪ This group does not receive the independent variable

▪ Used to compare results to show that the independent variable had an effect

▪

|Practice Problem #10: |

|Identify the independent variable, dependent variable, and some control variables in the following experiment: A scientists varies the amount of water he gives to|

|his tomato plants to see how it will affect their growth. |

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|Practice Problem #11: |

|Identify the independent variable, dependent variable, and some control variables in the following experiment: A scientist measures how much water evaporates over|

|time. |

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Practice Problem #12

Homer notices that his shower is covered in a strange green slime. His friend Barney tells him that coconut juice will get rid of the green slime. Homer decides to check this out by spraying half of the shower with coconut juice. He sprays the other half of the shower with plain water. After 3 days of “treatment” there is no change in the appearance of the green slime on either side of the shower.

1. What is being tested?

2. What is the control setup?

3. What is the experimental setup?

4. What should Homer’s conclusion be?

Practice Problem #13

Bart believes that mice exposed to microwaves will become extra strong (perhaps he’s been reading too much Radioactive Man(). He decides to perform this experiment by exposing 10 mice to microwaves for 10 seconds. He compared these 10 mice to another 10 mice that had not been exposed. His test consisted of a heavy block of wood that blocked the mouse food. He found 8 out of 10 microwaved mice were able to push the block away. 7 out of 10 of the non-microwaved mice were able to do the same.

1. What is being tested?

2. What is the control setup?

3. What is the experimental setup?

4. What are some standardized variables?

5. What should Bart’s conclusion be?

Q: Can all questions be solved using the scientific method?

A: No. In order to be solved using the scientific method, the question must involve ________________ that can be proven through scientific experimentation with measurable dependent variables. You cannot design a scientific experiment to measure ________________, thoughts, ________________, or other non-measurable variables and therefore questions involving these factors cannot be answered using the ________________ ________________.

|Practice Problem #14: |

|Decide whether or not the following questions can be answered solved using the scientific method. |

|1. Is the acceleration due to gravity is really 9.8 m/s2? |

|2. Is water made of hydrogen and oxygen atoms? |

|3. Are Twix bars better than Snickers bars? |

|4. Are Great Danes happier dogs than Poodles? |

|5. Do people act crazy during full moons? |

|6. Do small cars get better gas mileage than SUVs? |

|7. Does candy make kids happy? |

|8. Do anteaters eat more ants when it is sunny? |

Q: What is the difference between a hypothesis, a scientific theory, and a scientific law?

A: We already know that a hypothesis is a ________________ ________________ about how things work. Hypotheses require further testing to be proven true.

Ex: My locker won’t open because I’m not using the correct combination.

A ________________ ________________ is a possible explanation about the way things work that has been tested. A hypothesis becomes a scientific theory after ________________ testing has proven it true. Scientists are able to make ________________ based on theories.

Ex: Eating a high fat diet will result in high cholesterol.

A ________________ ________________ is a repeated observation about nature. Scientific theories become scientific laws after they have been repeatedly tested and proven ________________.

Ex: Newton’s 1st Law of Motion: For every action there is an equal and opposite reaction.

__________________________________________________________________________________________

Data Analysis and Graphing

Q: Why do we use graphs in science?

A: Graphs are ________________ representations of the results of our scientific experiments. Using graphs to analyze data allows us to find ________________ and ________________ in data that would otherwise be difficult, if not impossible, to interpret.

Q: Which types of graphs are we most likely to use in science?

A: There are three types of graphs you are most likely to use in science. These are:

1. ________________ ________________:

Line graphs are used to show data that changes for only ________________ item.

|Practice Problem #15: |

|Answer the following questions using the line graph: |

|Approximately how much hydrogen had been produced after 90 seconds had elapsed? |

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|How much time had elapsed when 117 mL of hydrogen had been produced? |

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2. ________________ ________________:

Bar graphs are used when we want to ________________ data for several different items or events.

|Practice Problem #16: |

|Answer the following questions using the bar graph: |

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|What is the approximate melting temperature of lead? |

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|Which metal has a melting temperature of approximately 1800 K? |

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3. ________________ ________________:

Pie charts are used when we want to see how the parts of something that ________________ ________________ to 100% of the data. Pie charts are usually ________________ and contain ________________.

|Practice Problem #17: |

|Answer the following questions using the pie chart: |

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|Which element makes up 48% of calcite? |

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|What percentage of calcite is made up of carbon? |

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Q: What are some tips for drawing good graphs and charts?

A: For a great graph, make sure to:

▪ Choose the right ________________ of graph for your data.

▪ Use graph ________________.

▪ Only draw ________________ graph per sheet of paper.

▪ Use a ________________ for all straight lines.

▪ Draw in ________________ colors.

▪ Be ________________.

▪ ________________ your graph.

▪ ________________ the x and y axes on line and bar graphs, including ________________ of measure.

▪ Use different ________________ on bar graphs and pie charts if possible.

▪ Always put the independent variable on the ________________

|Practice Problem #18: |

|Draw a graph or chart using the following data showing how mass changes |

|as temperature changes: |

|Temp (oC) |

|Mass (g) |

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|0 |

|100 |

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|20 |

|100 |

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|40 |

|100 |

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|60 |

|60 |

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|80 |

|20 |

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|100 |

|5 |

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|120 |

|3 |

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|140 |

|2 |

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|160 |

|1 |

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|Practice Problem #19: |

|Draw a graph or chart using the following data that shows the favorite |

|colors of a first grade class: |

|Color |

|# of Students |

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|Blue |

|7 |

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|Red |

|4 |

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|Yellow |

|6 |

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|Green |

|2 |

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|Pink |

|13 |

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|Orange |

|5 |

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|Practice Problem #20: |

|Draw a graph or chart using the following data that shows the % color |

|distribution of a bag of M&Ms: |

|Color |

|% of Bag |

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|Blue |

|24 |

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|Brown |

|13 |

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|Green |

|16 |

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|Orange |

|20 |

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|Red |

|13 |

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|Yellow |

|14 |

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For more graphing info, go to

__________________________________________________________________________________________

SI Reference Sheet

The International System of Units (SI) is accepted as the standard for measurement throughout most of the world. Frequently used SI units are listed in Table 1 and some supplementary SI units that you will use in this course are listed in Table 2. Keep this in your binder as a reference tool.

Table 1

|Frequently Used SI Units |

|Measurement |Name |Symbol |Conversion Factors |

| |SI Base Unit | |

|Length |meter |m |1 millimeter (mm) = 100 micrometers (µm) |

| | | |1 centimeter (cm) = 10 millimeters (mm) |

| | | |1 meter (m) = 100 centimeters (cm) |

| | | |1 kilometer (km) = 1000 meters (m) |

| | | |1 light-year = 9,460,000,000,000 kilometers (km) |

|Mass |gram |g |1 gram (g) = 1000 milligrams (mg) |

| | | |1 kilogram (kg) = 1000 grams (g) |

| | | |1 metric ton = 1000 kilograms (kg) |

|Time |second |s |1 second (s) = 1000 milliseconds (ms) |

| | | |1 minute (min) = 60 seconds (s) |

| | | |1 hour (hr) = 60 minutes (min) |

|Temperature |kelvin |k |0 kelvin (K) = -273˚Celsius (˚C) |

| | | |0˚Celsius (˚C) = 32˚Fahrenheit (˚F) |

|Volume |cubic meter or |m3 or L |1 cubic meter (m3) = 1 milliliter (mL) |

| |liter | |Note: The cubic meter is used to express volume of a solid, while the milliliter is used|

| | | |to express volume of a liquid |

Table 2

|Supplementary SI Units Used in Physics Essentials |

|Measurement |Unit |Symbol |Expressed in Base Units |

|Energy |joule |J |kg•m2/s2 |

|Force |newton |N |kg•m/s2 |

|Power |watt |W |kg•m2/s3 or J/s |

Sometimes quantities are measured using different SI units. In order to use them together in an equation, you must convert all of the quantities into the same unit. To convert, you multiply by a conversion factor. A conversion factor is a ration that is equal to one. Make a conversion factor by building a ration of equivalent units. Place the new units in the numerator and the old units in the denominator. For example, to convert 1.255 L to mL, multiply 1.255 L by the appropriate ratio as follows:

1.255 L x 1000 mL = 1255 mL Note: The unit L cancels just as if it were a number

1 1 L

Temperature measurements in SI are often made in degrees Celsius. Celsius temperature is a supplementary unit derived from the base unit kelvin. The Celsius scale (˚C) has 100 equal gradations between the freezing temperature (0˚C) and the boiling temperature of water (100˚C). The following relationship exists between the Celsius and kelvin temperature scales:

K = ˚C + 273

To convert temperatures from ˚F to ˚C, you can:

1. For exact amounts, use the equation at the bottom of Table 3, or

2. For approximate amounts, find ˚F on the thermometer at the left of Figure 1 and determine ˚C on the thermometer at the right.

Table 3

|SI Metric to English Conversions |

| |When you have: |Multiply by: |To find: |

|Length |inches |2.54 |centimeters |

| |centimeters |0.39 |inches |

| |feet |0.30 |meters |

| |meters |3.28 |feet |

| |yards |0.91 |meters |

| |meters |1.09 |yards |

| |miles |1.61 |kilometers |

| |kilometers |0.62 |miles |

|Mass and weight* |ounces |28.35 |grams |

| |grams |0.04 |ounces |

| |pounds |0.45 |kilograms |

| |kilograms |2.20 |pounds |

| |tons |0.91 |metric tons |

| |metric tons |1.10 |tons |

| |pounds |4.45 |newtons |

| |newtons |0.23 |pounds |

|Volume |cubic inches |16.39 |cubic centimeters |

| |milliliters |0.06 |cubic inches |

| |cubic feet |0.03 |cubic meters |

| |cubic meters |35.31 |cubic feet |

| |liters |1.06 |quarts |

| |liters |0.26 |gallons |

| |gallons |3.78 |liters |

|Temperature |Fahrenheit |5/9 (˚F – 32) |Celsius |

| |Celsius |(9/5 x ˚C) + 32 |Fahrenheit |

* Weight as measured in standard Earth gravity

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