What is science?

Science is the organized search for the truth

We ask questions and try to find the answers– Why do we have seasons?– Where will an earthquake occur?– How do cancer cells grow?– What am I allergic to?– What happens if I mix two chemicals together?– Why do I need to wear a seatbelt?– Why are pandas endangered?

Look at these questions

• You can make a hypothesis (an educated guess) but you can’t stop there.

• How will you support your hypothesis? What is your evidence?

• To support your hypothesis, you will need data or evidence.

• To collect evidence, you will need to use the proper tools.

Which of the following is the best instrument to use to answer our questions?

Why did you choose a ruler?

• Rulers are used to measure length.

T. Trimpe 2008 http://sciencespot.net/

Length

• The distance between two points

Which type of ruler should we use?

Metric makes calculations and measurements much easier!

We use metric measurements in science class.

• Why?– It’s easier to convert (m to cm vs. yards to

feet) – no fractions!

- More countries use it!

Non-metric countries: USA, Myanmar, Liberia

Measure Carefully and Always use Metric!

http://www.cse.lehigh.edu/~gtan/bug/localCopies/marsOrbiter

The Metric System

So how do I use a metric ruler?

• Metric rulers are divided into centimeters and millimeters.

• 10mm = 1 cm

• 100 cm = 1 m

• Step 1:  You must align the left edge of the ruler with the left edge of the object you are measuring.

• Step 2:   Look at the ruler and count the number of centimeters of the object shown.  

• Answer: The length is 6.8 cm or 68 mm

Measuring Length

Ruler: http://www.k12math.com/math-concepts/measurement/ruler-cm.jpg

How many millimeters are in 1 centimeter?

What is the length of the line in centimeters? _______cm

What is the length of the line in millimeters? _____ mm

What is the length of the line to the nearest centimeter? ________cm

HINT: Round to the nearest centimeter – no decimals.

1 centimeter = 10 millimeters

2.8

28

3

Try it!

• How long is your paper?– In cm?– In mm?

• How wide is your paper?– In cm?– In mm?

Look at these questions

• Form a hypothesis:– Which line segment is longer? _______– Which person is taller? _________

• Collect some data• Form a conclusion and support your answer.

Are the gray horizontal lines parallel or do they curve?How will you support your hypothesis?

Masking Tape

• Invented in 1923 by Richard Drew working at the 3M company

Painting a car two-toned

Clear Tape

The stickiest tape ever!

• Is this claim true? Which tape is actually the stickiest? How you test it?

• Problem we will solve:– Which type of tape is the stickiest?

• Tape A Tape B Tape C

Hypothesis

• If I roll a marble down a ramp, then it will roll the least distance on the _________ tape because it is the stickiest.

Sample of tape at bottom of ramp.

Materials

• 3 types of tape– (list them in the boxes)

• Blocks of wood/books• 2 rulers• marbles

Identify parts of the experiment

a. Independent variable

-Type of tape

b. Dependent variable

-Distance marble rolls

c. Control variables

-height of ramp, marble used, release point on ramp

Procedures and data collection

• Follow the steps of the experiment and carefully measure and record your data.

Graphing

• Bar graph

• Title your graph (give a descriptive title- what did you test?)

• Title each axis– Independent variable on the bottom– Dependent variable on the side– Include units!

Descriptive Title

0 10

2030

Dis

tanc

e M

arbl

e Ro

lled

(cm

)

Types of Tape

Scotch Masking Packing

Conclusion1. Which is the stickiest tape?2. Is your hypothesis supported or not?3. Provide evidence (use actual numbers) to

explain why your hypothesis was supported or not.

4. Why do we have to do five trials?5. What were some sources of error (are your

results 100% accurate)?6. What did you learn from this activity? How could

you apply this new knowledge to your life?