SCIENTIFIC METHOD

Choose a topic

Collect Information Independent Variable: is the ONE factor or condition that is intentionally changed by the experimenter. Dependent Variable: is the factor or condition that may be affected as a result of changing the independent variable. The dependent variable is what you measure or observe to obtain your results. Constant Variable (Control): are all the factors or conditions that must be kept the same in an experiment.

Time it takes for color to dissolve IMAGINE Will M & M color dissolve faster in water or in another clear liquid? Independent Variable: Type of clear liquid Dependent Variable: Time it takes for color to dissolve Constant Variable (Control): Color of M&M’s, amount of liquid, type of M&M, time when dropped in

What amount of sunlight makes pea plants grow tallest? Independent Variable: Amount of sunlight Dependent Variable: Growth rate of pea plants Constant Variable (Control): How much water, what type of soil, altitude

Size of soda, style of soda, age of soda Which type of soda has more sugar: Pepsi, Coke or RC? Independent Variable: Type of soda Dependent Variable: Amount of sugar Constant Variable (Control): Size of soda, style of soda, age of soda

Type of ball, color, age of ball Is the height of a ball’s bounce affected by the height from which the ball is dropped? Independent Variable: Height of drop Dependent Variable: Height of bounce Constant Variable (Control): Type of ball, color, age of ball

Size of battery, use of battery, temperature Which battery will last the longest: Energizer or Duracell? Independent Variable: Brand of battery Dependent Variable: Life of battery Constant Variable (Control): Size of battery, use of battery, temperature

Thermometer used, time of year, time of day, location Is the water temperature of Lake Michigan affected by the depth of the water? Independent Variable: Depth of water Dependent Variable: Temperature of water Constant Variable (Control): Thermometer used, time of year, time of day, location

Collect Information IV = Independent Variable DV = Dependent Variable CV = Constant Variable 1. The factors that are kept the same in an experiment. CV 2. This is also known as the responding variable. DV 3. This is the one thing that is changed by the experimenter. IV 4. This is also called the manipulated variable. IV 5. This is the factor that is affected as a result of changing the manipulated variable. DV 6. This variable must be measurable to obtain results. DV 7. There may be many of this type of variable in an experiment. CV

How many drops of water will fit on the head of a penny? Form a Hypothesis How many drops of water will fit on the head of a penny? 1. Predict (Random Guess): How many drops do you think can fit on the head of a penny? Turn a penny heads-up and count the drops of water squeezed from an eyedropper without spilling over. 2. How many drops actually fit on the head of the penny? Since you now have some experience with putting water on a coin, you will be better suited to form a hypothesis for this research question: “How many drops of water will fit on the head of a nickel?” 3. Write your hypothesis:

4. Which do you think is more accurate: your hypothesis about water on a nickel (#3) or your prediction about water on a penny (#1)? Explain. My prediction for the nickel was more accurate because I learned something from doing the penny first. 5. What factors did you consider when writing your hypothesis about water on a nickel? I realized the nickel was bigger, so it should hold more drops. 6. How many drops actually fit on the head of the nickel? 7. How did your results (#6) compare to your hypothesis (#3) 8. Was your hypothesis for the nickel more or less accurate than for the penny? Why?

“How many drops of water will fit on the head of a dime?” 9. Write your hypothesis: Turn a dime heads-up and count the drops of water squeezed from an eyedropper without spilling over. 10. How many drops actually fit on the head of a dime? 11. How did your dime results (#10) compare to your hypothesis (#9) 12. Which hypothesis (penny, nickel, or dime) was most accurate?

Form a Hypothesis A hypothesis does not just predict what will happen in an experiment, but it specifically tells how one variable (IV) might affect another variable (DV). A hypothesis can be written in a specific way to express this relationship between the Independent and Dependent Variables. (Remember that a hypothesis is a guess about the results; it does not have to be correct.) A hypothesis can be written as an “IF...THEN…” statement. When the variables are added into the hypothesis, the format becomes “If IV, then DV.” Think of it like this: “If I change the IV, then I think the result (DV) will be _________.” Don’t forget that the hypothesis is your prediction about what will happen, so you will have to add your own words and thoughts.

EX: Research Question: Does salt water freeze faster than fresh water? IV: Type of Water DV: Time water takes to freeze Possible Hypothesis: If I test salt water and fresh water, then fresh water will freeze faster.

WRITING A HYPOTHESIS IV: Type of music DV: Time to quiet a baby Which type of music quiets a crying baby faster: jazz, classical or rock? IV: Type of music DV: Time to quiet a baby Hypothesis: If I play _______ music, then a baby will quiet faster.

WRITING A HYPOTHESIS IV: Color of recycling bin DV: 2. Does the color of the recycling bins - red or blue - affect the number of cans recycled at school? IV: Color of recycling bin DV: Number of cans recycled Hypothesis: If I use a ____ bin, then there will be more cans recycled

Spreading of food coloring WRITING A HYPOTHESIS 3. Does the temperature of water affect how quickly food coloring spreads through it? IV: Temperature of water DV: Spreading of food coloring Hypothesis: If I make water ______, then it will mix food coloring quicker.

WRITING A HYPOTHESIS IV: Hours of daylight DV: Number of eggs 4. Is the number of eggs a chicken lays affected by the hours of daylight? IV: Hours of daylight DV: Number of eggs Hypothesis: If I let a chicken have _____ hours of daylight, then it will lay more eggs.

WRITING A HYPOTHESIS IV: Material used to hold weight DV: 5. Will a rubber band or a string hold more weight without breaking? IV: Material used to hold weight DV: Amount of weight held Hypothesis: If I use a _______, then it will hold more weight.

If I chew Brand ___, then I will get more sugar. WRITING A HYPOTHESIS 6. Which type of gum contains the most sugar: Brand A, Brand B or Brand C? IV: Brand of gum DV: Amount of sugar Hypothesis: If I chew Brand ___, then I will get more sugar.

M&M Lab

Independent Variable: Type of liquid Research Question: Will M&M color dissolve faster in water or in another clear liquid? Materials: 2 beakers, water, another clear liquid, 2 identical plain M&M’s, stopwatch SEE WORKSHEET Variables: Independent Variable: Type of liquid Dependent Variable: Time for M&M to dissolve Constant Variable: Color of M&M, amount of liquid, temperature of liquid Hypothesis: IF I drop two identical M&M’s into water and vinegar, THEN the M&M will dissolve faster in the...

Procedure: (Read all the steps before you begin) 1. Use 2 cups. Stick a piece of masking tape as a label on the side of each cup. Write “A” on the first beaker, “B” on the second. 2. Put 100 ml of room temperature water in Beaker A. Put 100 ml of room temperature vinegar in Beaker B. 3. Choose 2 of the same color plain M&M’s. Drop one M&M into each cup at EXACTLY the same time. Do not touch the candy or the beakers once you have started the experiment. 4. Carefully observe what is happening to the M&M’s. In the table below, record the time it takes for the color to completely come off each M&M. Record Data: The effect of different liquids on the time it takes for color to dissolve. LIQUID TIME Beaker A: WATER 3:46 Beaker B: VINEGAR 4:06

The color ran off of it, spread out and the M&M began to crack. Draw Conclusions: 1. What happened to the M&M in Beaker A? The color ran off of it, spread out and the M&M began to crack. 2. What happened to the M&M in Beaker B? The M&M in the vinegar did not dissolve as fast. 3. Why is it important that both M&M’s are the same color? Because we are testing the liquid, not the color. 4. Was your hypothesis supported? Why or why not? 5. What can you conclude about different liquids and how well they remove M&M color? Water seems to be better at removing color from M&M’s than vinegar.

Breathing Rate

Breathing Rate 1. Background Information: Oxygen is essential to life. We use the oxygen we breathe and the food we eat to produce energy. Physical activity increases our need for energy; increasing the use of oxygen and nutrients. The body can store some of the things it needs to function. However, oxygen cannot be stored for more than a few minutes at a time. At rest the blood holds about a quart of dissolved oxygen, but it is constantly being used by the cells to produce energy during respiration. The respiratory system must work all the time to supply enough oxygen to the body. 2. Question: What is the effect of exercise on breathing rate? Write your hypothesis statement. IF I exercise, THEN my breathing rate will...

3. Materials: Stopwatch 4. Procedures: Step 1. Work with a partner. One person will be the participant; the other will be the recorder. The recorder is responsible for starting, stopping and timing. The participant is responsible for counting the breaths he/she takes during the investigation. Step 2. The participant will sit very still for 1 minute; breathing normally. At a signal from the recorder, the participant will count how many complete breaths (in and out) he/she takes in one minute. The recorder will watch the clock and start and stop the participant. Step 3. Record the data in the table below. Step 4. Repeat the process while walking in place for 1 minute. Record data. Step 5. Repeat the process while jogging in place for 1 minute. Record data. Step 6. Switch participant/recorder roles and repeat experiment.

Respiration Rate (breaths/minute) 5. Data: Positions Respiration Rate (breaths/minute) Sitting 8 Walking 10 Jogging 14 6. Data Analysis: Describe the relationship between breathing rate and exercise. When you exercise your breathing rate goes up. If both data tables are filled in, what are the independent and dependent variables? The position is the independent variable and the breathing rate is the dependent variable. 7. Conclusions: Did your data support your hypothesis? Describe your results.

Our results did not completely match our hypothesis because we were up and down and had a hard time counting the number of breaths. My results matched my hypothesis because the breathing rate went up the more I exercised.