To See Which Surface Is the Roughest

Apparatus:

Sandpaper

Wood

Paper

Polythene

Foam

Car

Diagram:

surface car force metre

Table

Method: I set up the apparatus by:-

- placing the surface on the table.

2- I then put the car on top of the surface.

3- I hooked the string on to the force metre.

4- I tested five surfaces and found my result by pulling the string slowly till the car moved from the surface and read the result off the force metre.

5- I presented a result table for each surface and designed a graph.

Surface

Force

Sandpaper

4.55

Wood

.85

Paper

2.25

Polythene

2

Foam

2.7

Conclusion: What I had referred in my prediction, the sandpaper resulted to be the roughest surface. I was wrong when I said paper will be the roughest but it was wood. The results showed wood as the least rough surface.

Evaluation: Sandpaper made the car exert the most force to move and it took the most time to move. The result showed the greater the friction the less movement there was. It was less likely to move on sandpaper then it was on the other surfaces. The other surfaces showed very little friction acting on the car, which made it difficult to slow the car down. I could have made the experiment better by applying cello tape on to the surface so it remains flat. I could have also made it better by testing the result four or five times to get an accurate reading.