A New Way to Hear

Gecko's Feet

The Scientific Method

- A method for investigating, learning, and questioning the world around us.

- A specific thought process that includes the following stages:

- Question- Purpose- Hypothesis- Experiment (Materials and Procedure)- Results and Observations- Conclusion/Discussion

Weird Science!

Variable Identification

- Identify the dependent, the independent and the control variable(s) in the following situations.

Pick and describe a variable below then pop the balloon to check your answer.

The variable that is purposely changed in an

experiment.

The factor that may change as a result of the

variable being tested.

Factors that are all kept the same except for the variable changed.

Situation 1

Tom planted bean seeds in 3 rectangular shape containers. The ends of 10 seeds were pointed up. Ten seeds were pointed down and ten were pointed sideways. All seeds were covered with soil.

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Amount of growth of the plant

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lessame type of rectangular container, same type of soil, same amount of

light, same amount of temperature and same temperature - What others can you think of?

Situation 2

Alissa tested an electromagnetic system she made. She wrapped a wire around a battery and a nail. Different sized nails were used and the number of paper clips the electromagnet picked up was measured by how many paper clips were picked up.

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How many paper clips the electromagnet picked up.

Con

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Same brand, age and size of battery, same type and length of wire, wire should be wrapped around the nail the same number of times, nails should be exactly alike except for size--What others did you think of?

Situation 3In

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Fans should be: same voltagesame number of blades tested from same distance and number of timestested from same settingfan blade should have same diameterWhat other variables can you think of to control?

Pete wanted to find out which brand of fan would produce the greatest amount of wind force. He used a wind gauge to measure wind speed.

Dep

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Amount of wind force

Situation 4

Does the height from which an egg is dropped effect the size of the

egg's splatter?

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Size of the egg's splatter

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lessame size and type of egg, egg should be positioned the same each time,

eggs should be same temperature, should be dropped on the same type of surface,---What other's control variables can you think of?

You grow African violets for a hobby and notice that violets kept at warmer temperatures grow better.

Forming a Hypothesis

Offers an explanation for an observation.

Refers to only ONE independent variable.

Written as a statement, not a question.

Testable by experimentation.

Written as an "if...then..." statement.

Investigate the effect of varying...

on the following...

Temperature Leaf width

Light intensity Activity of rolly pollys

Soil pH Plant height at 6 months

Salt concentration Height eggs float

If the __________________ is _______________,

then the ________________ will ______________.independent variable describe how you change it

dependent variable describe the effect

Hot & Cold Plants

Problem: How does temperature affect plant growth?

Hypothesis:

Method:1. Plant four bean seeds in identical pots containing the same amount and kind of soil.

2. Label the pots A, B, C, and D. Place them in the same sunny window.

3. On Mondays and Fridays, water each plant with 125 mL of water at the following temperatures:

Plant A: Room temperature (25* C)Plant B: Hot tap water (60* C)Plant C: Ice water (5* C)Plant D: Boiling water (100* C)

4. At the end of 30 days, measure the height of the plants in centimeters..

INDEPENDENT VARIABLE

DEPENDENT VARIABLE

CONTROLLED VARIABLESIf the __________________ is _______________,

then the ________________ will ______________.

independent variable

describe how you change it

dependent variable

describe the effect

Numbered steps

Specific, like a recipe

Includes multiple trials

A list of materials Contains:* an independent variable* a dependent variable* a control* constants

The Experiment...

Graphing VariablesDrag the correct label to each axis.

D- Dependent Variable

I- Independent Variable

X axis

Y axis

Check answers on next page when finished.

DRY MIX and Variables

D- Dependent VariableR- Responding Variable Y- Y axis

M - Manipulated VariableI- Independent VariableX axis

A clever way to remember where each variables goes on a graph is the saying DRY MIX . Discus and create another clever way to remember.

Problem: Will fresh eggs float in salt water?

Hypothesis:

An Eggsperiment...Can an Egg Float?

Materials:A raw egg, in its shell Table salt400 mL beaker Warm tap waterMetric rulerPlateGraduated cylinder Plastic spoon

Procedure:1. Fill beaker with 250 mL warm water.

2. Place egg into the beaker.

3. Measure the distance from the bottom of the beaker to the top of the egg in centimeters.

4. Remove the egg and place it on the plate.

5. Add 5 g of salt to the water and stir until dissolved.

6. Place egg back in the beaker and measure.

7. Repeat Steps 5 & 6 using a total of 10, 15, and 20 g of salt.

8. Remove the egg. Discard the salt solution. Rinse the glass thoroughly and repeat Steps 1-7 three more times, for a total of four trials.

If the __________________ is _______________,

then the ________________ will ______________.independent variable

describe how you change it

dependent variable

describe the effect

Dependent

vari

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Independent variable

Recording & Graphing Data

Amount of Salt

Trial 1 Trial 2 Trial 3 Average

0 mL

5 mL

10 mL

15 mL