Mystery Footprints

Case #2

One Saturday morning Nina saw the three musketeers in the mall. Jenny, Brittany, and Mitzi called themselves by that name because they always were together.

"I've been shopping for sandals," Jenny told Nina. "But I have such a wide foot nothing seems to fit. We've been looking everywhere."

"And it's been slow going," Mitzi added. "On account of Brittany's-" "I know," Nina said looking at Brittany, "I heard you sprained your ankle in gym yesterday. Does it still hurt a lot?"

"It's okay as long as I move really slowly," Brittany told her. "We're going to get ice cream at the Just Desserts Shop now. Want to join us?" "Better not,” Nina said, “ Max is meeting me at home. See you later."

Source: http://kids.mysterynet.com/quicksolve/

Nina was taking a short cut through Harborville's city park when she saw Mr. Hansen kneeling beside a new sidewalk. The city maintenance man frowned as she drew closer. "Somebody jumped right in the middle here while the cement was still wet," he said, pointing at two narrow footprints embedded in the concrete. "Now I'll have to rip out this section and re-do it. Sure can't leave the sidewalk looking like this!"

"Any idea of who did it?" Nina asked.

"A kid over there on the slide said that girls named Brittany, Mitzi, and Jenny were the only ones near here. But he doesn't know which one ruined my sidewalk."

"I know who did it," Nina declared.

How did Nina figure it out?

The footprints were narrow. Jenny had wide feet. Because of her sprained ankle, Brittany would not

have jumped. Since Mitzi was the only one left, she had to be the guilty one.

1.2 The Way Science Works

The Way Science Works• Key Ideas

• How Can I think like a scientist?• How do scientists measure things?

• Why it matters?• Thinking logically, or like a scientist, can help you solve

daily problems.• Which method of training is helping me improve my

running times?

1.2 The Way Science Works

The Way Science Works• Activity

• Investigate the impact that adding various amounts of fertilizer has on plant growth. Think about what you would need to do to conduct this experiment.

Disclaimer****** - Thinking has been shown to challenge the capacity of your brain, I, Mr. Shull am not responsible for any resulting injuries of this activity, SO DON’T HURT YOURSELF!

1.2 The Way Science Works

The Way Science Works• How can I think and act

like scientist?• Identifying problems, planning experiments, recording observations, and correctly reporting data are some of the most important science skills.

• Scientists approach a problem by thinking logically.

1.2 The Way Science Works

The Way Science Works• The Scientific Method

• a series of steps followed to solve problems including collecting data, formulating a hypothesis, testing the hypothesis, and stating conclusions• The scientific method is

a description to follow, not an exact path that has to be followed.

They are all intertwined!

1.2 The Way Science Works

The Way Science Works

Observe

• Observe/watch anything in nature

Formulate a

question• What do you

want to know?

Research and

collect data

• What is already known about your question

Form a hypothesi

s• Propose an

answer to your question based on observations, research, and data

Test the Hypothes

isObserve

Draw Conclusio

ns• Did your

results support your hypothesis? If not modify the hypothesis based on observations

Observations give additional data for a new hypothesis

1.2 The Way Science Works

The Way Science Works• hypothesis: a possible

explanation or answer that can be tested• Scientists test a hypothesis by doing

a controlled experiment. • controlled experiment: an

experiment in which the variables that could affect the experiment are kept constant (controlled) except for the one that you want to measure

• variable: a factor that changes in an experiment in order to test a hypothesis• Only Change 1

Variable!!!!!!!!!!!!!!!!!!!!!!!!

1.2 The Way Science Works

The Way Science Works• Experiments test ideas.

• No experiment is a failure!• The results of every

experiment can be used to revise the hypothesis or plan tests of a different variable

• Peer Reviewed Research: Research that has been reviewed by other scientists.

Other scientists perform the experiments themselves to

confirm your results.

1.2 The Way Science Works

The Way Science Works• These experiments are always being performed as

new information becomes available to us• Earth’s Systems• Space• Biology• Hibb’s Boson particle• Forensics (DNA cases)

• Which leads us to…..

1.2 The Way Science Works

The Way Science Works• Science and technology are

heavily dependent on one another.

• What special tools can you think of that scientists use?• Ex –

• Telescopes• Particle Accelerators• Satellites• Many, many, many, many,

many, many, many, many more.

• Microscope• Types?

• New discoveries in technology can lead to new discoveries in science.

House dust mite

1.2 The Way Science Works

The Way Science Works• Well, how do scientists

measure things?• Feet, inches, yards,

gallons, cups, quartz?• Do you realize how hard

those are to convert?• Scientists use standard

units of measure that together form the International System of Units, or SI.• Units of measure are

easily converted and are the same throughout the world.

1.2 The Way Science Works

The Way Science Works• SI units are used for

consistency.• SI has seven base units. • Derived Units: Combinations

of base units. • Kilo-gram• Centi-meter• Milli-second

1.2 The Way Science Works

The Way Science Works• SI (Le Système Internationale d’Unités)

1.2 The Way Science Works

The Way Science Works• SI prefixes are for very large and very small

measurements.• The prefixes are multiples of ten.• SI Prefixes for small measurements

• Centi-meter = .01 meters

1.2 The Way Science Works

The Way Science Works• SI prefixes for large measurements

• Kilo-gram = 1,000 grams• Kilo-meter = 1,000 meters• Mega-watt = 1,000 watts

Metric System• The metric system is based on a base

unit that corresponds to a certain kind of measurement

• Length = meter• Volume = liter• Weight (Mass) = gram

• Prefixes plus base units make up the metric system • Example:

• Centi + meter = Centimeter• Kilo + liter = Kiloliter

Metric System• The three prefixes that we will use the most

are:• kilo• centi• milli

kilo hecto deca

Base Unitsmetergramliter

deci centi milli

Metric System• So if you needed to measure length you would

choose meter as your base unit• Length of a tree branch

• 1.5 meters • Length of a room

• 5 meters • Length of a ball of twine stretched out

• 25 meters

Metric System• But what if you need to measure a longer

distance, like from your house to school?• Let’s say you live approximately 10 miles from school

• 10 miles = 16093 meters • 16093 is a big number, but what if you could add a

prefix onto the base unit to make it easier to manage:• 16093 meters = 16.093 kilometers (or 16.1 if

rounded to 1 decimal place)

Metric System• These prefixes are based on powers of

10. What does this mean?• From each prefix every “step” is either:

• 10 times larger or

• 10 times smaller• For example

• Centimeters are 10 times larger than millimeters• 1 centimeter = 10 millimeters

kilo hecto deca

Base Unitsmetergramliter

deci centi milli

Metric System• Centimeters are 10 times larger than

millimeters so it takes more millimeters for the same length

1 centimeter = 10 millimetersExample not to scale

1 mm

1 mm

1 mm

1 mm

1 mm

1 mm

1 mm

1 mm

1 mm

1 mm

1 cm

40

41

41

40

Metric System• For each “step” to right,

you are multiplying by 10• For example, let’s go from a base unit to

centi1 liter = 10 deciliters = 100 centiliters

2 grams = 20 decigrams = 200 centigrams

kilo hecto decameterliter

gramdeci centi milli

( 1 x 10 = 10) = (10 x 10 = 100)

(2 x 10 = 20) = (20 x 10 = 200)

Metric System• An easy way to move within the metric

system is by moving the decimal point one place for each “step” desiredExample: change meters to centimeters1 meter = 10 decimeters = 100 centimeters

or1.00 meter = 10.0 decimeters = 100. centimeters

kilo hecto decameterliter

gramdeci centi milli

Metric System• Now let’s try our previous example from

meters to kilometers:16093 meters = 1609.3 decameters = 160.93 hectometers =

16.093 kilometers

• So for every “step” from the base unit to kilo, we moved the decimal 1 place to the left (the same direction as in the diagram below)

kilo hecto decameterliter

gramdeci centi milli

Metric System• If you move to the left in the diagram, move the

decimal to the left

• If you move to the right in the diagram, move the decimal to the right

kilo hecto decameterliter

gramdeci centi milli

Metric System• Now let’s start from centimeters and

convert to kilometers

400000 centimeters = 4 kilometers

400000 centimeters = 4.00000 kilometers

kilo hecto decameterliter

gramdeci centi milli

Metric System• Now let’s start from meters and convert to

kilometers

4000 meters = 4 kilometerskilo hecto deca

meterliter

gramdeci centi milli

kilo hecto decameterliter

gramdeci centi milli

• Now let’s start from centimeters and convert to meters4000 centimeters = 40 meters

Metric System• Now let’s start from meters and convert to

centimeters

5 meters = 500 centimeterskilo hecto deca

meterliter

gramdeci centi milli

kilo hecto decameterliter

gramdeci centi milli

• Now let’s start from kilometers and convert to meters

.3 kilometers = 300 meters

Metric System• Now let’s start from kilometers and convert

to millimeters

4 kilometers = 4000000 millimetersor

4 kilometers = 40 hectometers = 400 decameters = 4000 meters = 40000 decimeters = 400000 centimeters = 4000000

millimeters

kilo hecto decameterliter

gramdeci centi milli

Metric System• Summary

• Base units in the metric system are meter, liter, gram

• Metric system is based on powers of 10• For conversions within the metric system, each “step” is 1 decimal place to the right or left

• Using the diagram below, converting to the right, moves the decimal to the right and vice versa

kilo hecto decameterliter

gramdeci centi milli

1.2 The Way Science Works

The Way Science Works• Units of measure that tell you a number, or

quantity?• Quantitative!• Measurements quantify your observations.

• length: a measure of the straight-line distance between two points

• mass: a measure of the amount of matter in an object

• volume: a measure of the size of a body or region in three-dimensional space

• weight: a measure of the gravitational force exerted on an object

1.2 The Way Science Works

The way Science works• Observation

• Something you can see • Inference

• Coming to a conclusion based on your observations

1.2 The Way Science Works

What Inferences can you make from your observations of this picture?

1.2 The Way Science Works

The Way Science Works• Review Questions!