Group Members: Charlie, Tiff Lay, Mika, Azfar, Jerald and Ika
1. Analyzing Friction
How effective are different types in producing friction on different types of surfaces in TAS?
For this experiment, we set out to analyze how much friction is produced by two types of surfaces in the school. In order to do so, we sampled four different types of shoes that [we thought] represented the type of shoes worn in the TAS community. We then measured the mean static friction and mean kinetic friction produced by each shoe on each surface.
i. Variables
Independent - The types of shoes and surfaces Dependent - The [amount of] friction produced, both the static and kinetic friction
Two different types of surfaces were used: the hallway and the tracks. Four different types of shoes were equally used on both surfaces: cleats, flats, flip flops and casual shoes.
a. Cleats b. Flats c. Flip flops d. Casual shoes
ii. Materials
Force Probe (unit in N Newtons) Logger Pro and Computer Two 500g mass Four different shoe types Two different surfaces Stopwatch Meter stick
iii. Procedure
1. Place the two masses into the shoe, one inside towards the toe part of the shoe and the other in the heel part in order to the distribute the mass equally. 2. Hook the force probe onto the shoe, and connect the force probe to Logger Pro. 3. Pull the shoe at a horizontal angle parallel to the surface. 4. Start collecting data as you pull the shoe along the surface; keep pulling the shoe for one meter. 5. Repeat steps 1 to 4 for five trials. 6. Repeat steps 1 to 5 for each shoe. 7. Repeat steps 1 to 6 for both surfaces. 8. Calculate the mean kinetic and static friction for each trial for each shoe for each surface. 9. Calculate the mean kinetic static friction of all the trials for each for each surface.
iv. Processed Data
a. Mean static friction and kinetic friction of shoes in surface 1 (hallway)
Shoes
Static Friction (N)
Kinetic Friction (N)
Cleats
8.374
11.678
Flats
2.327
8.020
Flip flops
4.591
9.267
Casual shoes
6.356
10.632
b. Mean static friction and kinetic friction of shoes in surface 2 (tracks)
Shoes
Static Friction (N)
Kinetic Friction (N)
Cleats
6.283
9.738
Flats
4.103
8.601
Flip flops
6.063
9.714
Casual shoes
6.151
10.659
v. Data Analysis
*error in graph titles; "friction" instead of "force" From the bar graphs above, we infer that the mean force static differs significantly for each shoe between the surfaces. We see that the flats, for example, only produces a mere 2N of force static i.e. it takes only 2N of force to move flats from rest in the hallway, suggesting that either the hallways are rather too slippery for flats or the design of flats pose some hazards, or both. In contrast, we see that it takes 8N of force static to move cleats, thereby demonstrating the unsuitability of using cleats in the hallway (though, that would not be a concern for many TAS students save athletes who, for some reason, may walk in the hallways with cleats on). Casual shoes and flip flops on the other hand, fare better (less for the latter), producing a mean force static of about 6N and 4.5N respectively in the hallway. Though flip flops do better than flats to produce friction, it is still arguably low. However, if we analyze the mean force static for shoes on the tracks, we see that all produce a relatively higher amount of friction, suggesting that it is arguably safe to walk on the tracks with any of the footwear used in the experiment.
vi. Evaluation
The nature of our investigation, as well the nature of friction itself, forces us to be empirical and generalize many things; therefore there is no particular law/general equation that we can come up with that applies to all types of shoes on all types of surfaces. Much evaluation can be produced. In regards to the methodology, it is rather unrealistic to use cleats as an example of shoes the TAS community would wear around in school, particularly the hallways, but it is justified choice as we attempted to investigate the amount of friction produced by these footwear on the track. Though, perhaps we could have chosen to use running shoes instead of cleats. Additionally, there were some difficulties we encountered during the procedure. We found that it was rather difficult to control the horizontal angle one pulls the shoes at. As a result, we found that some of the data we generated were unusable. Some showed a higher mean force static than the mean force kinetic, which could not have been produced other than as a result of a distortion in the experiment. Though there are many possible scenarios, we highly believe that the main distortion is the inability to keep the hand pulling the shoe constantly parallel to the surface. In retrospect, there was no real need to control the distance or the time it took for the shoe to be pulled across a meter, rather; what we should have done was to find a way to control the angle. Perhaps, we could have designed something to be attached to the force probe perpendicular to the surface in order to keep the angle constant.
2. Light Intensity
Purpose
The purpose is to find the light settings for the ideal educational environment, and finding the implications of the current settings on the average student.
Background
Ideal Setting for Study: Different tasks require different light settings. As we mostly partake in writing and studying in the educational environment the minimal light intensity is around 1000 lux. The lighting used in the classrooms is fluorescent lights. Every classroom has a window. Often teachers will turn off all lights in a classroom while teaching off of a projector.
Variables:
Variables
Explanation of Variables:
Independent
- Light type (sunlight, fluorescent light, LCD screen light) - Direction in which light enters classroom
- Investigating all different types of light that typically enter classrooms will help to find out whether our classrooms will fit the ideal light settings for studying. - Different classrooms have different positions in the school relevant to the sun’s positioning in the sky.
Dependent
- Light intensity (lux)
- Measuring light intensity will allow us to compare with research to determine optimum light settings for studying.
Control
- Positioning of probe in relation to light source - Extraneous light
- Same positioning of probe to light source will allow us to compare data. - Setting conditions of the classroom to only sunlight/only fluorescent/only LCD light will ensure extraneous light doesn’t affect the dependent variable.
1. Turn off all lights and open all curtains to allow sunlight into the classroom. 2. Position the light probe at a set height and distance from the window, preferably at the center of the window, and record distance/height measurements. 3. Set the light switch on the light probe to 0-6000 lux. 4. Click “Collect” in logger pro, and gather data for 10 seconds. 5. Repeat steps 1-4 in at least two other classrooms that have different angles from which sunlight enters. Use the measurements for height and distance from window that you used in step two. 6. Close all curtains (to mimic a possible classroom setting) and turn on all lights. 7. Position the light probe at the same set distance from the fluorescent lighting in the classroom as from the window. 8. Click “Collect” in logger pro, and gather data for 10 seconds. 9. Close all curtains and lights (to mimic another possible classroom setting). 10. Position the light probe at a normal distance in which people sit from the computer screen. 11. Click “Collect” in logger pro, and gather data for 10 seconds.
Sunlight: Laptop:
Data Collection
[table here]
Data Analysis
The fluorescent lamps had the highest average light intensity, as observed from the tabular and graphical data. We measured all the light sources from a meter away, however while we measured sunlight a meter away from the window, its source is in fact much further away. It would be impractical and difficult to measure 1 meter away from the sun. In addition to that, we are not one meter away from and facing the fluorescent lamps when we work, and neither are we 1 meter away from our computers. Also, we are not always the same distance and direction away from the windows. But in order to compare the light intensity of these different sources, we have to control them to a certain extent.
Effects of Fluorescent light: Fluorescent light is Ultra Violet light transformed into visible light. Due to this process the relative intensity of light in certain narrow band lengths are disproportional. This is what causes colors to look harsh or “unhealthy” under fluorescent lighting. Effects of Excessive Fluorescent light on Humans:
Dizziness
Headaches
Blurred
Eyestrain
Floaters
Skin rashes
Sinus problems
Fatigue
Nausea
Sleep disturbances
Mood swings
Irritability
Conclusion
The graph above clearly shows that the intensity of the LCD screen light is much lower than the sunlight and fluorescent lighting and therefore doesn't contribute greatly to the overall lighting of the classroom. The low lux of the screen light is at an acceptable range for light reading though. There is also almost a 1000 lux difference between the sunlight in some classrooms and fluorescent lighting. The results could indicate that there is too much fluorescent lighting in the classrooms, which would produce the side effect mentioned above. However, before we hasten to replace our fluorescent lights with full spectrum lights, we need to acknowledge that full spectrum lights have their own limitations as well. Like natural sunlight, full spectrum lights, as its name implies, projects the full spectrum of wavelengths. However, unlike natural sunlight, the full spectrum lights possess the limitation of artificial lights: they oscillate at the same rate as fluorescent lights. While the full spectrum lights are not as harmful to our body, they are less energy efficient, and more harmful to the environment. As a result, we have to find a middle ground between our body's health and the environment's health. Thus, until we can get around the limitations of different artificial lights, we should work towards a solution which requires incorporating more natural light into the classroom.
Group Members: Charlie, Tiff Lay, Mika, Azfar, Jerald and Ika
1. Analyzing Friction
How effective are different types in producing friction on different types of surfaces in TAS?
For this experiment, we set out to analyze how much friction is produced by two types of surfaces in the school. In order to do so, we sampled four different types of shoes that [we thought] represented the type of shoes worn in the TAS community. We then measured the mean static friction and mean kinetic friction produced by each shoe on each surface.
i. Variables
Independent - The types of shoes and surfacesDependent - The [amount of] friction produced, both the static and kinetic friction
Two different types of surfaces were used: the hallway and the tracks. Four different types of shoes were equally used on both surfaces: cleats, flats, flip flops and casual shoes.
a. Cleats
b. Flats
c. Flip flops
d. Casual shoes
ii. Materials
Force Probe (unit in N Newtons)Logger Pro and Computer
Two 500g mass
Four different shoe types
Two different surfaces
Stopwatch
Meter stick
iii. Procedure
1. Place the two masses into the shoe, one inside towards the toe part of the shoe and the other in the heel part in order to the distribute the mass equally.2. Hook the force probe onto the shoe, and connect the force probe to Logger Pro.
3. Pull the shoe at a horizontal angle parallel to the surface.
4. Start collecting data as you pull the shoe along the surface; keep pulling the shoe for one meter.
5. Repeat steps 1 to 4 for five trials.
6. Repeat steps 1 to 5 for each shoe.
7. Repeat steps 1 to 6 for both surfaces.
8. Calculate the mean kinetic and static friction for each trial for each shoe for each surface.
9. Calculate the mean kinetic static friction of all the trials for each for each surface.
iv. Processed Data
a. Mean static friction and kinetic friction of shoes in surface 1 (hallway)v. Data Analysis
*error in graph titles; "friction" instead of "force"
From the bar graphs above, we infer that the mean force static differs significantly for each shoe between the surfaces. We see that the flats, for example, only produces a mere 2N of force static i.e. it takes only 2N of force to move flats from rest in the hallway, suggesting that either the hallways are rather too slippery for flats or the design of flats pose some hazards, or both. In contrast, we see that it takes 8N of force static to move cleats, thereby demonstrating the unsuitability of using cleats in the hallway (though, that would not be a concern for many TAS students save athletes who, for some reason, may walk in the hallways with cleats on). Casual shoes and flip flops on the other hand, fare better (less for the latter), producing a mean force static of about 6N and 4.5N respectively in the hallway. Though flip flops do better than flats to produce friction, it is still arguably low. However, if we analyze the mean force static for shoes on the tracks, we see that all produce a relatively higher amount of friction, suggesting that it is arguably safe to walk on the tracks with any of the footwear used in the experiment.
vi. Evaluation
The nature of our investigation, as well the nature of friction itself, forces us to be empirical and generalize many things; therefore there is no particular law/general equation that we can come up with that applies to all types of shoes on all types of surfaces. Much evaluation can be produced. In regards to the methodology, it is rather unrealistic to use cleats as an example of shoes the TAS community would wear around in school, particularly the hallways, but it is justified choice as we attempted to investigate the amount of friction produced by these footwear on the track. Though, perhaps we could have chosen to use running shoes instead of cleats. Additionally, there were some difficulties we encountered during the procedure. We found that it was rather difficult to control the horizontal angle one pulls the shoes at. As a result, we found that some of the data we generated were unusable. Some showed a higher mean force static than the mean force kinetic, which could not have been produced other than as a result of a distortion in the experiment. Though there are many possible scenarios, we highly believe that the main distortion is the inability to keep the hand pulling the shoe constantly parallel to the surface. In retrospect, there was no real need to control the distance or the time it took for the shoe to be pulled across a meter, rather; what we should have done was to find a way to control the angle. Perhaps, we could have designed something to be attached to the force probe perpendicular to the surface in order to keep the angle constant.2. Light Intensity
Purpose
The purpose is to find the light settings for the ideal educational environment, and finding the implications of the current settings on the average student.Background
Ideal Setting for Study:Different tasks require different light settings. As we mostly partake in writing and studying in the educational environment the minimal light intensity is around 1000 lux. The lighting used in the classrooms is fluorescent lights. Every classroom has a window. Often teachers will turn off all lights in a classroom while teaching off of a projector.
Variables:
- Direction in which light enters classroom
- Different classrooms have different positions in the school relevant to the sun’s positioning in the sky.
- Extraneous light
- Setting conditions of the classroom to only sunlight/only fluorescent/only LCD light will ensure extraneous light doesn’t affect the dependent variable.
Materials
- Light probe- Tape measure
- Clamp
- Clamp stand
- Laptop
Method
1. Turn off all lights and open all curtains to allow sunlight into the classroom.2. Position the light probe at a set height and distance from the window, preferably at the center of the window, and record distance/height measurements.
3. Set the light switch on the light probe to 0-6000 lux.
4. Click “Collect” in logger pro, and gather data for 10 seconds.
5. Repeat steps 1-4 in at least two other classrooms that have different angles from which sunlight enters. Use the measurements for height and distance from window that you used in step two.
6. Close all curtains (to mimic a possible classroom setting) and turn on all lights.
7. Position the light probe at the same set distance from the fluorescent lighting in the classroom as from the window.
8. Click “Collect” in logger pro, and gather data for 10 seconds.
9. Close all curtains and lights (to mimic another possible classroom setting).
10. Position the light probe at a normal distance in which people sit from the computer screen.
11. Click “Collect” in logger pro, and gather data for 10 seconds.
Sunlight:
Laptop:
Data Collection
[table here]Data Analysis
The fluorescent lamps had the highest average light intensity, as observed from the tabular and graphical data. We measured all the light sources from a meter away, however while we measured sunlight a meter away from the window, its source is in fact much further away. It would be impractical and difficult to measure 1 meter away from the sun. In addition to that, we are not one meter away from and facing the fluorescent lamps when we work, and neither are we 1 meter away from our computers. Also, we are not always the same distance and direction away from the windows. But in order to compare the light intensity of these different sources, we have to control them to a certain extent.Effects of Fluorescent light:
Fluorescent light is Ultra Violet light transformed into visible light. Due to this process the relative intensity of light in certain narrow band lengths are disproportional. This is what causes colors to look harsh or “unhealthy” under fluorescent lighting.
Effects of Excessive Fluorescent light on Humans:
Conclusion
The graph above clearly shows that the intensity of the LCD screen light is much lower than the sunlight and fluorescent lighting and therefore doesn't contribute greatly to the overall lighting of the classroom. The low lux of the screen light is at an acceptable range for light reading though. There is also almost a 1000 lux difference between the sunlight in some classrooms and fluorescent lighting. The results could indicate that there is too much fluorescent lighting in the classrooms, which would produce the side effect mentioned above. However, before we hasten to replace our fluorescent lights with full spectrum lights, we need to acknowledge that full spectrum lights have their own limitations as well. Like natural sunlight, full spectrum lights, as its name implies, projects the full spectrum of wavelengths. However, unlike natural sunlight, the full spectrum lights possess the limitation of artificial lights: they oscillate at the same rate as fluorescent lights. While the full spectrum lights are not as harmful to our body, they are less energy efficient, and more harmful to the environment. As a result, we have to find a middle ground between our body's health and the environment's health. Thus, until we can get around the limitations of different artificial lights, we should work towards a solution which requires incorporating more natural light into the classroom.Works Referenced
http://ergonomics.about.com/od/lighting/a/lightleveltask.htm
http://ps.fass.org/cgi/content/full/88/1/20