paper towel investigation

1. Paper Towel Investigation D. Crowley, 2008

2. Thursday, August 25, 2011

3. Initial Questions Initially you need to brainstorm what we need from a paper towel? What makes a paper towel good? How do paper towels work? What do we need it to do? Why do we use paper towels? How could you compare the difference between two or more types of paper towel? Note down what you would do if you spilt a liquid at home? Paper towels are there to absorb spillages – they need to absorb as much liquid as they can, yet still remain strong enough so they do not fall apart It is also important that they absorb the liquid as quickly as possible, limiting the damage the liquid may do…

4. Key Words During your investigation you will come across some key words: - Accurate: a measurement that is close to the true value (accuracy can be increased by controlling the key variables) Precision: this is a more precise measurement, which can be achieved by using a smaller scale Reliability: the experiment needs to be repeatable – if someone else did the experiment then they should get exactly the same results: this comes from repeating your experiment Dependent variable – what is changed by the experiment (what you are going to measure) Independent variable – what you change Control variable(s) – what you are going to keep the same, making the experiment more accurate

5. Demo Look at the demo of the paper towels – How can you identify which is the most absorbent towel? How can you identify which is the strongest towel?

6. Introduction Initially write you introduction for the paper towel investigation Note your aim (what we are doing); why we are doing it and what tests which will carry out and why I.e. What makes a paper towel good? How do paper towels work? What do we need it to do? Why do we use paper towels? How could you compare the difference between two or more types of paper towel?

7. Method Your task is to now consider what methods you are going to use to measure both the absorbency and the strength of the paper towels How are you going to make your experiment: - Accurate (as close to the true value as possible) Reliable (so someone else can repeat this experiment and get similar results) Precise (how many readings are going to be taken and how can you ensure each repeat is completed in the same way) Complete a step-by-step guide to completing your experiment Note your independent variable (thing you change) and how you will change this Note your dependent variable(s), and how you will measure this What data are you collecting / recording

8. Method - Absorbency To find the absorbency of a paper towel we need to measure its initial mass (dry) and measure the mass of a beaker we are going to place it in We can then fill this beaker up with water, leave it for a minute then turn the beaker upside down so any excess water drips off When there are no more drips we can find the mass of the paper towel in the beaker to find which absorbed the most water – take this mass away from the initial mass of the beaker

9. Method - Strength