Inquiry in Action
Before you start....
Download and complete the attached proforma.
Which paper towel brand will soak up the most water?
Independent variable (we are changing)
Type of paper towel
Dependent variable (we are measuring)
Measure the amount of water soaked up
Controlled variables (all other variables need to be controlled)
The size of the paper towel, time of towel in water
The place where the water has been spilled
The measuring container
can you think of anything else ?
How will you measure the amount of water soaked up by each towel?
Will completing the investigation just once be sufficient?
Paper towels (3 types A, B, C), water (coloured), measuring device, container, scissors.
1) Cut the paper towels so that they are all the same size and shape
2) Fill a container with 30 ml of coloured water
3) Put the paper towel into the container and wait for 30 seconds
4) Pull out the towel and wait until the towel has stopped dripping
5) Then measure the amount of water remaining in the containing using a measuring cylinder
6) You need to repeat this investigation with each brand of paper towel, and you need to repeat the investigation three times each.
Results (see the table and graph attached)
The graph shows that the paper towel 3 absorbs the most water and paper towel 1 absorbs the least amount of water. So the best paper towel is paper towel 3.
The science behind this phenomena relates to the design of the paper which impacts on the capillary action and consequently the absorbency.
PMI Positive Negative and Improvement
Negative - the paper towel dripped on the bench and not in the container
Improvement - the measuring cylinder was only accurate to 2 ml, more trials would improve the accuracy of the investigation