Observe the 2 pennies in front
of you.
Record your observation.
Observation Penny 1 Penny 2
Color Dull Shiny
2) Question
Develop a question or
problem that can be
solved through an
experiment.
Q) Will lemon juice clean
the dull coin?
After you search the internet
and the books for information
you find out that:
Lemon, vinegar and tomato sauce
can be use to clean silver and
metal objects
4) ExperimentMake a test to test
whether the hypothesis
is correct.
1) Put the coin in the
lemon juice.
2) Wait for 5 min. and
record the results.
6) ConclusionThe answer to the
question (you state
whether your hypothesis
was right or wrong).
The lemon juice cleans
the dull coin.
In any experiment there are 3 variables:
Independent
variables
Dependent
variables
Controlled
variables
Let’s look at each type….
Independent (input) variable
This is the thing that you decide to change.
Example 1:
Investigating how a weight
affects the length of an elastic band.
You decide the weight to put,
so:
Weight is the independent
variable.
Example 2:
Investigating how the rate of cooling of a
beaker depends on the initial temperature.
You decide the initial temperature,
so:
initial temperature is the
independent variable.
Students of different ages were given the
same jigsaw puzzle to put together. They
were timed to see how long it took to finish
the puzzle.
Example 3:
You decide the ages of the students,
so:
Different ages of the students is the
independent variable.
The higher the temperature of water, the
faster an egg will boil.
Example 4:
You decide the temperature of water,
so:
Different temperatures of water is the
independent variable.
The temperature of water was measured at
different depths of a pond.
Example 5:
You decide the depth of water,
so:
Depth of water is the independent
variable.
This is the variable that changes as a result.
It is the variable that you measure.
Example 1:
Investigating how a weight
affects the length of an elastic band.
You measure the resulting length
of the elastic band, so:
Length is the dependent
variable.
Dependent (outcome) variable
Example 2:
Investigating how the rate of cooling of a
beaker depends on the initial temperature.
You measure the temperature
every minute as it cools, so:
temperature is the dependent
variable.
Students of different ages were given the
same jigsaw puzzle to put together. They
were timed to see how long it took to finish
the puzzle.
Example 3:
You measured time, so:
Time taken to finish the puzzle is the
dependent variable.
The higher the temperature of water, the
faster an egg will boil.
Example 4:
You measure the time the egg takes to
boil, so:
Time is the dependent variable.