Friction Lab

There are three different types of variables in this experiment. The independent variable in this experiment is the surface areas. The controlled variable in the experiment is the block of wood being tested. Lastly, the dependent variable is the friction force.

II. Materials and Methods

In preparation for doing our experiment, we gathered the following materials: Styrofoam, granite, felt, construction paper, tabletop surface, tape, a pen, a plastic cup, string, a paperclip, stopwatch, washers, and a block of wood. First, we taped down the pen as a barrier, so the block of wood would not fall off the table when it was sliding across the surface being tested. Then, we tied the string around the block of wood and attached the paperclip to the sting. To the paperclip, we attached the plastic cup. Once we finished that, we began the experiment.

The first surface area we tested was the construction paper. We laid the construction paper on the table, an inch away from the pen. Then we placed the block on top of the paper. The cup was now hanging over the table edge. We began to add small washers until the block began to move. Once the block began to move, we started the experiment. We started the stopwatch and let the block slide across the surface area. When the block hit the pen, we stopped the stopwatch. We repeated the same steps for the other four surface areas: granite, felt, tabletop, and Styrofoam. We recorded our data in a table.

III. Data

Independent Variable

Number of Washers

Time

Mass

Force of Friction

Paper

5 small washers

39 ms

75.5g

755 N

Felt

8 small washers

68 ms

271.8g

2,718 N

Table

8 small washers

65 ms

20.8g

,208 N

Granite

4 small washers

48 ms

60.4g

604 N

Styrofoam

6 small washers

47 ms

90.6g

906 N

IV. Conclusion

Shannon and I did answer our question. We thought different surface areas would affect the force of friction, and it did. The smoother the surface the faster the block would move, and the lower the force of friction. Where as the rougher or bumpier the surface, the slower the block would move, and the higher the force of friction because more force was needed to move the object.

The felt had the most friction. I think this for many reasons. First, it is the highest force of friction. Second, the block was the slowest while sliding across the felt. I think this surface had the most friction because the material is not smooth. It is rough and it is harder to glide across. More force is needed to get an object across it.

I think a few areas were made in the experiment. I think the placing of the block of wood should have been more precise. I think timing also could have been more concise. For future experiments, I think there should exact measurement where the block should be placed and the person using the stopwatch should be more careful and concise while timing the experiment.

This experiment was applied to real-life. It was proven my theory was correct. The friction between the tires of your automobile and the road determines your speed. Depending on the weather conditions or the material the road is made of, can affect your speed. When it is raining, your car tends to go faster because you have a layer of water lubricant under your tires. Your car can move faster because less force is needed for the car to move. On the hand, when you are driving on a gravel road, you need greater force to cause motion because the surface is not smooth as asphalt paved road, which is flat.