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

Length The distance between two points

Which type of ruler should we use?

The Meter Originally defined as a physical quantity of nature. 1/10,000,000 of the distance from the equator to the pole. Section 1.4

The Meter The meter is now defined by the distance light travels in a vacuum/time. Section 1.4

Length British Standard Unit = Foot, originally referenced to the human foot. –Why is this a problem? –What happens to that measurement when a new king is crowned? Section 1.4

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!

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: 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

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?

Today’s lab Measuring the distance a marble will roll on tape of differing stickiness. Problem we will solve: –Which type of tape is the stickiest?

Graphing Title your graph (give a descriptive title!) Title your axis –Independent variable on the bottom –Dependent variable on the side –Include units!

Conclusion 1.Which is the stickiest tape? 2.Is your hypothesis supported or not? 3.What data did you use to support your answer to #2? 4.Why do we have to do five trials? 5.What were some sources of error? 6.What did you learn from this activity? How could you apply this new knowledge to your life?