Transcript 6.variables - Mitchell Intermediate School

CATALYST
1.) Pick up your HOMEWORK PACKET and graded
quizzes in the graded work folders.
2.) Answer the following questions on the LEFT PAGE:
What is an independent variable?
What is a dependent variable?
General Science – Tues, 09.02.2008
Agenda
• Quick Reminders
• Quiz Tracker
• Variables
•Independent
•Dependent
• Practice
• Wrap Up
General Science – Tues, 09.02.2008
Quick Reminders
•Bring science fair notebook tomorrow!
•HW Packet #3 Due Friday, 09.05.2008.
• Quiz #3 on Friday, 09.05.2008.
General Science – Tues, 09.02.2008
QUIZ TRACKER
Objectives
SWBAT:
 Articulate what independent and
dependent variables are.
 Write a statement which contains
independent and dependent
variables.
Variables
09.02.2008
Variable
Definition
 “varius” (Latin)
 means “changing”
 “able” (Latin)
 is used to form words that describe (adjectives) and
means “capable or worthy of”
 So when you combine the two roots of the word
variable you get the meaning:
 Something that is capable of changing
Variables
Origin
09.02.2008
-Varius (“changing”) + able (“capable of”) =
variable (“capable of changing”)
Variable
In a scientific experiment, a variable is any
factor or trait or condition that can exist in
differing amounts or types.
EX:
 The effect of weather conditions on the amount of
citrus fruit produced.
Why are variables important in
scientific inquiry?
Scientists use variables in their
experiments to search for
Relationships in nature.
Variables
09.02.2008
Origin
-Varius (“changing”) + able (“capable of”) =
variable (“capable of changing”)
Importance
- Helps find relationships in nature
Why are variables important in
scientific inquiry?
 In other words, they design an experiment so that
changes to one item cause something else to vary
(change) in a predictable way.
Variables
09.02.2008
Origin
-Varius (“changing”) + able (“capable of”) =
variable (“capable of changing”)
Importance
-Helps find relationships in nature
- Setup expmts. to change one item & see
how affects other items
Types of Variables
 An experiment usually has three kinds of variables:
independent, dependent, and controlled.
 Today we are only going to talk about independent and
dependent variables.
Independent Variable
 An independent variable (IV) is a variable
in the experiment that the experimenter
changes or manipulates
Independent variable is
what I can change.
Variables
09.02.2008
Origin
-Varius (“changing”) + able (“capable of”) =
variable (“capable of changing”)
Importance
-Helps find relationships in nature
- Setup expmts. to change one item & see
how affects other items
Types
- Independent (IV) – experimenter changes
(“Independent = I change”)
Independent Variable
As the scientist changes
the independent variable,
he or she observes what
happens.
Dependent Variable
The dependent variable is what
changes when the
independent variable changes
The dependent
variable is what
we measure
Variables
09.02.2008
Origin
-Varius (“changing”) + able (“capable of”) =
variable (“capable of changing”)
Importance
-Helps find relationships in nature
- Setup expmts. to change one item & see
how affects other items
Types
-Independent (IV) – experimenter changes
(“Independent = I change”)
- Dependent (DV) – what changes when IV
changes; what we measure
Dependent Variable
The scientist focuses his or her observations on
the dependent variable to see how it responds to
the change made to the independent variable.
The new value of the dependent variable is
caused by and depends on the value of the
independent variable.
Practice Identifying Variables
QUESTION 1
How much water flows through a faucet at different openings
(closed, half open, fully open)?
INDEPENDENT VARIABLE
DEPENDENT VARIABLE
Variables
Types
09.02.2008
-Independent (IV) – experimenter changes
(“Independent = I change”)
-Dependent (DV) – what changes when IV
changes; what we measure
Examples
- Q1: How much water flows through a
faucet at different openings?
Practice Identifying Variables
QUESTION 1
How much water flows through a faucet at different openings
(closed, half open, fully open)?
INDEPENDENT VARIABLE
Water faucet opening (closed, half open, fully open)
DEPENDENT VARIABLE
Amount of water flowing measured in liters per minute
Variables
Types
09.02.2008
-Independent (IV) – experimenter changes
(“Independent = I change”)
-Dependent (DV) – what changes when IV
changes; what we measure
Examples
- Q1: How much water flows through a faucet
at different openings?
IV1: Water Faucet Opening (Closed / Half
Open / Fully Open)
DV1: Amount of Water Flowing
Practice Identifying Variables
QUESTION 2
Does heating a cup of water allow it to dissolve more sugar?
INDEPENDENT VARIABLE
DEPENDENT VARIABLE
Practice Identifying Variables
QUESTION 2
Does heating a cup of water allow it to dissolve more sugar?
INDEPENDENT VARIABLE
Temperature of the water measured in degrees Celsius
DEPENDENT VARIABLE
Amount of sugar that dissolves completely measured in grams
Practice Identifying Variables
QUESTION 3 (ON LEFT PAGE)
Does an electric motor turn faster if you increase the voltage?
INDEPENDENT VARIABLE
DEPENDENT VARIABLE
Practice Identifying Variables
QUESTION 3 (ON LEFT PAGE)
Does an electric motor turn faster if you increase the voltage?
INDEPENDENT VARIABLE
Voltage of the electricity measured in volts
DEPENDENT VARIABLE
Speed of rotation
Variables OVERVIEW
Independent Variables
What I change
Dependent Variables
What is being measured
SUMMARY & PRACTICE
Take 3 minutes to write your
summary.
When you are done, begin
working on your HW Packet!