Which cup of tea is the sweetest?
Obviously the one with the most sugar.
Or is it?
Only if the amount (volume) of tea is the same in each cup.
To be really sure you will also need to make sure the tea is at the same temperature.
Variable are all
the things that could change during an investigation.
In a bouncing ball investigation many things could change from
one experiment to the next.
A different ball.
A different drop height.
Try and think of two more.
Remember you should only change one thing in your experiments.
This called the independent variable.
As a result of your experiment your results should show
something changing. (How high the ball bounces might change).
This is called a dependent variable.
The factors you keep the same in your experiments (fair test)
are called control variables.