Measurement, Graphing, Experimental Design, and The Scientific Method

Measuring Mass Mass = The measure of how much matter is in an object. Matter = Anything that has mass & takes up space. Tool Used: Triple-Beam Balance = Specialized scale with a pan and three beams. Each beam has sliding masses called riders. The right end of the beam has a pointer that indicates whether the mass on the pan is equal to the mass shown on the beams.

Measuring Volume Tools Used: Volume = The amount of space an object takes up. Units: cm3 or mL Tools Used: Metric Ruler/Meter Stick = Each number is 1 centimeter (cm). Each smaller line between the numbers is 1 millimeter (mm). Graduated Cylinder = A narrow, cylindrical container marked with horizontal measurement lines (mL).

Measuring Temperature Temperature = A measure of the average kinetic energy of the particles in an object. Kinetic Energy = Energy of Motion Warmer objects: Particles move faster + Bump into each other  Generate heat Cooler objects: Particles move slower + Rarely bump into each other  Do not generate heat Lack of Heat = Cool

Low Temperature vs. High Temperature

Measuring Temperature Tool Used: Thermometer = Horizontal markings along side in units of degrees Celsius (oC). Avg. Human Body Temp. = 20 oC – 25 oC Freezing Point of Water = 0 oC Boiling Point of Water = 100 oC

Measuring Length Length = The measurement of something along its greatest dimension. Tools Used: Metric Ruler Meter Stick = Marked off in centimeters (cm) and usually millimeters (mm).

SI Units Kilo Hecto Deca Basic Units Deci Centi Milli K H D Grams (g) Meters (m) Liters (L) King Henry Drinks Unusually Dark Chocolate Milk 0.001 Km 0.01 Hm 0.1 Dm 1 m 10 dm 100 cm 1000 mm

SI Unit Practice 4 m = ______cm 7 L = ______ KL 14 g = ______ mg Step 1: Add decimal to end if no decimal Step 2: Determine which way to move decimal (remember acronym!) Step 3: Move decimal appropriate number of spaces over. Step 4: You have arrived at the proper conversion! 4 m = ______cm 7 L = ______ KL 14 g = ______ mg 20 cm = ______ mm 100 Kg = ______ dg

SI Unit Practice Answers 4 m = _400_cm 7 L = _.007_ KL 14 g = _14,000_ mg 20 cm =__200_ mm 100 Kg = _1,000,000_ dg

Graphing

Line Graph Bar Graph Histogram Pie Chart Type of Graph Purpose Picture Track changes over short and long periods of time. Compare changes over the same period of time for more than one group. Bar Graph Compare things between different groups or to track changes over time. Use when changes are larger. Histogram Use continuous data to represent ranges of data rather than categories. Pie Chart Use when you are trying to compare parts of a whole.

Types of Variables Independent Variable Dependent Variable Controlled Variables Variable being tested Changed/Manipulated by the scientist The only factor that affects the outcome of the experiment. Condition that results from changes made to the independent variable Depends on the independent variable Responds to changes made to the independent variable Used as a constant and  unchanging standard of comparison.

Properly Labeling the Graph D R Y M I X Dependent Responding Y-axis Manipulated Independent X-axis Dependent Variable (Responds) Independent Variable (Manipulated) Y X D R Y M I X

Rules for Graphing DO NOT connect your first point to (0,0) unless you are SPECIFICALLY given the point (0,0) in the set of points. ALWAYS label your Title, X-axis, and Y-axis. ALWAYS start labeling your X and Y axis scales at 0. Create an APPROPRIATE scale on BOTH the X and Y axis. Each marking should represent the same distance as the first marking. Make sure your plotted points are CLEAR and in the correct spot on the graph. Create a KEY if you are plotting more than one set of values on a graph.

Title X-axis Labeled Y – axis Labeled Scales start at (0,0) Scales are made with equal units separating each marking Clear points are drawn First point does not connect to (0,0) No key needed

The Scientific Method

Scientific Method - A way to ask and answer scientific questions by making observations and doing experiments. Steps: Ask a Question Do Background Research Construct a Hypothesis Test Your Hypothesis by Doing an Experiment Analyze Your Data and Draw a Conclusion Communicate Your Results

Step 1: QUESTION Step 2: RESEARCH You see something…you’re confused by it…you decide you want to find out more about it… Step 2: RESEARCH You looked up information to find out more about your problem…now you have knowledge of the problem and can generate a reasonable explanation...

Step 3: HYPOTHESIS “Prediction/Educated Guess” You made an educated guess using the background information you researched…now you can test your idea… Step 4: EXPERIMENT You carry out the experiment and gather new information about the problem…

Step 6: SHARE YOUR RESULTS Step 5: ANALYZE DATA You gained valuable information about the problem…now you have to tell others what you learned… Step 6: SHARE YOUR RESULTS You told others how the data relates to the problem…now you can keep experimenting…a scientists work is never ending…

Scientific Experiments

Scientific Experiments Follow the scientific method & test a hypothesis. Have multiple trials in order to be valid. Must be controlled or results are invalid. What does this mean?

Controlled Experiments There are two main groups in scientific experiments: Control Group: This group receives no experimental treatment. Experimental Group: This group is the test group that receives experimental treatment.

A Proper Experiment Scientists want to test a new product that claims to boost energy for 5 hours after consumption. They have 200 volunteers to test the product on. There are 100 test subjects in the control group and 100 test subjects in the experimental group. The people in the control group receive a fake product (a bottle filled with water to drink). The people in the experimental group receive the energy boosting product. The scientists perform the experiment, collect data, and draw conclusions.

In our experiment… The independent variable is the energy boosting product. The dependent variable is the amount of energy each volunteer has. The amount of energy depends on whether or not the volunteer was given the energy boosting product, or the independent variable.

Valid Experiments Valid experiments have multiple trials To eliminate outliers Prevent against biased results Be able to get an of average many data points

Observation vs. Inference A statement based upon one or more of the 5 senses. Observation: A prediction based upon a prior observation. May or may nit be true. Inference:

Types of Observations Qualitative: Description using the 5 senses. Quantitative: Description using number values. Types of Observations

Scientists recognize that there can be change over time Scientists recognize that there can be change over time. Therefore, trends that were once thought to be true can change. Sometimes a reason for change is error. A scientists goal is to stay current and up to date. They seek knowledge. This is an on going process. Scientists check other scientists’ work. Sometimes, they find errors or different solutions to the same problem. This offers an alternative solution to the problem, an more experiments need to be performed to find the best answer. Other times they validate the previously learned information. The Scientist Mindset