Warm-Up Quiz

• What are the 5 steps of the scientific method?–S – State the Problem–P – Propose a Hypothesis–E – Experiment–R – Record and Analyze Data–M – Make a Conclusion

IDENTIFYING VARIABLES

Variable

Able toChange

Variable: A factor that can change in an experiment. Every experiment has two – one is the cause, the other is the effect.

Cause and Effect

• Does crushing a sugar cube effect the rate at which the sugar dissolves in the water?

What is the cause and what is the effect?

Crushing the sugar cube will

effect how long it

takes to dissolve.

Crushing the sugar cube is what we

predict will be the cause.

The time it takes to

dissolve is what we will see the

effect on.

This is called the Independent Independent

VariableVariable.

This is called the Dependent Dependent VariableVariable.

The variable being tested in an experiment.

Independent variable

is the variable that you observe and measure.

Dependent variable

Experiment Title: Does the age of a person gets married effect their chances of getting a divorce?

Experiment Title: Does fertilizer affect plant height?

Experiment Title: Is there are relationship between the weather and how students behave?

IV- DV-

IV- DV-

IV- DV-

Age Chances of divorce

fertilizer

weather

Plant height

behavior

Check for Understanding

• Does brushing your hair make it grow faster?

1)Identify the independent variable.

2)Identify the dependent variable

Check for Understanding

• Do car accidents increase your car insurance cost?

1)Identify the independent variable.

2)Identify the dependent variable.

Any variable we keep the same in order to make sure it isn’t what’s causing the effect.

CONSTANT

Practice with Constants

• Does fertilizer affect plant height?– Independent Variable: fertilizer– Dependent Variable: plant height

How can we be sure that the fertilizer is effecting the plant height?

We must have a constant to make sure that the fertilizer is the only factor affecting plant height.

– Constant: Type of plant used, brand of fertilizer, amount of fertilizer

Practice with Constants

• Does the temperature outside effect the chances a person will get the flu?

-IV: Temperature outside

-DV: Chances a person will get the flu

-Constant: Person

Check for Understanding

• What effect does a car’s speed have on gas mileage?

1) Identify the Constant.

Check for Understanding

• Does adding salt to water affect the temperature at which it boils?

1)Identify the Constant.

• Write the hypothesis for A and D: 

• Make a list of the constants and variables