2. Methods

Methods of experimentation

1. Acquire sandpaper sheets, floor tiles, spring balance and weights(Inclusive of weight stand), as well as safety equipment(Gloves and if necessary, safety goggles).
2. Prepare necessary safety equipment when scrubbing the tiles.
3. Sort the floor tiles into 2 groups. Note that there are 11 floor tiles in total.
4. First group of tiles consists of 6 tiles, labelled A, B, C, D, E, F. Second group of tiles consists of 5 tiles, labelled B2, C2, D2, E2, F2. Note that the first tile, A, is reused in the later part of the experiment.
5. Attach the set of weights(Inclusive of stand) to the hook of the spring balance.
6. Prepare the sandpaper sheets for use. NOTE: Tile A is the experimental control, and is not to be treated with the sandpaper.
7. Starting with the first group of tiles, scrub the tiles with the sandpaper sheet(s) with the respective durations as shown below.

Tile	Treatment Duration (Seconds)
A	0
B	30
C	60
D	90
E	120
F	150

8. Using the set of weights and the spring balance, drag the weights across the first tile, A. Reading of force is to be recorded at eye level.
9. Repeat the process of dragging the weights across the respective tile two more times, for a total of three times, inclusive of the first time.
10. After we have the 3 sets of data for the first tile, calculate the average amount of force recorded in the spreadsheet.
11. Record the amount of force recorded by the spring balance in a spreadsheet.
12. Repeat for the remaining tiles of the first set, which includes tiles B, C, D, E and F. The remaining tiles are to be treated with the sandpaper for the respective durations as shown in the table above. They are also to have the set of weights dragged across, thrice, after they are treated with sandpaper for the set duration as shown.
13. For the second group of tiles, consisting of : A, B2, C2, D2, E2, F2.
14. Since tile A is to be reused, we can simply drag the set of weights across the tile surface immediately to record the amount of force, as well as the average amount of force.
15. For the remaining tiles, B2, C2, D2, E2, and F2, treat them with the sandpaper sheets for the same duration as the table shown respectively. Example: Tile B2 is to be scrubbed with sandpaper for 30 seconds, same as Tile B.
16. Once the tiles have been finished being treated with sandpaper, repeat process of dragging weight across respective tile surface thrice, and recording of force, as well as calculation of the average amount of force.
17. Once all tiles have been treated and the average amount of force has been calculated, compile all the data in a spreadsheet.
18. Using the data in the spreadsheet, plot a line graph showing the average amount of force recorded against the different treatment durations of the respective tile.