Monday, November 24, 2014
Thursday, November 20, 2014
Friction Lab
Experiment 1 Surfaces Pressed Together
VM: As the Fn increases, the Ff increases constantly.
MM; Ff=(90.5 N/N)x Fn+0.02N why does it say 90.5?
Slope: For every 1 N added to the Fn, the Ff increases by 0.5N.
Y-int: When the Fn is at 0 N, the Ff is at 0.02N.
Experiment 2 Velocity
2. How does the velocity affect the Ff?
Prediction: As the velocity increases, the force of friction decreases.
IV: Velocity
DV: Ff
CV: Fn, Surface materials
Procedure
We pulled the block at different speeds: slow, medium, fast. We were able to measure the different velocities with the Dual Force Sensor, and determine the relationship between the velocity and Ff.
VM: As the different speeds are applied, the Force of friction remained the same.
Experiment 3 Surface Area on Ground
How does the surface area affect the Force of friction?
Prediction: The bigger the surface area, more Force of Friction is present.
IV: Surface Area
DV: Force of Friction
CV: Speed and Surface Material
Secondary Experiment: Change the side of the block.no secondary here -you changed the side of the block to manipulate the surface area
Procedure
We measured the Force of Friction using a piece of wood and used all the different sized surface areas. We made sure the the speed and the surfaces remained the same in order for our experiment to be as accurate as possible.
VM: The surface area does not affect the force of friction.
where is the graph from schoology?
Conclusions
Introductory Paragraph
Through these series of experiments, our goal was to determine the relationships between the surface area, velocity, and force of friction. We were able to find out that the only factors that have an affect on the friction is Fn and surface. Throughout the three experiments, we kept the surface constant in all three of the experiments. We changed the the Fn, velocity, and the surface area in order to find out how they affect the force of friction.
Experiment 1
According to our first experiment, all of the graphs are linear because of the same slope. The slopes are the same because the same surface was used. The velcro side was 0.2 N/N while the rubber side was 0.9 N/N. The slope of the velcro side was less, because there was less friction against the surfaces. By adding weights, it shifted the graphs but they still remained proportionally the same. The slope also remained the same. We concluded that as the Fn increases, so does the Ff.What is the equation? What do we call the slope?
Experiment 2 & 3
We were able to find out that the velocity and the surface do not have an affect on the Ff. The Ff will continue to remain the same if and only if the Fn and surface stay constant. The change in velocity or surface are do not affect the force of friction. My group predicted that the bigger the surface area, the bigger Ff would be. Our prediction was wrong, as we concluded that it does not affect the relationship whatsoever.
Drawing Conclusions
It is possible for two people wearing identical shoes to have different forces of friction. The material of the surface they are standing on and their Fn would be factors that could affect the Ff. The different surfaces could have affect the friction, based on whether the surfaces would have less or more friction. For example, tile floors would have less friction than carpet. The weights of the individuals also have an affect on the forces of friction. Based on our first experiment, it was proven that the more Fn applied, the more Ff would be present. If one of the people weighed more, that person would have more force of friction. The only way the forces of friction could be equal is if they both weigh the same and are standing on same surface material. The surface area and velocity would not change the force of friction.
Errors
For next time, we could be more careful and take more accurate data. An error that occurred during our experiment was when we failed to zero the program, resulting in data that was not accurate. If we knew what we did wrong during that time, we would have saved time and extra work. Thankfully we were able to fix the problem before it was too late.
Journal Statement
After completing the lab report, I felt more confident in my lab skills. I understood the concept and what we were trying to achieve in the experiment. Through this lab, I understood how to determine the relationship between 2 or more factors by changing variables and keeping one constant. In order to improve the experience, we could pay closer attention to what kinds of data we were collecting and ask questions if conflicts arose.good!
Pre-Lab Questions
1. How is the friction force affected when the surfaces are pressed together more?
Prediction: When there is more weight added in order to manipulate the normal force, the force of friction increases.
IV: Normal Force
DV: Force of Friction
CV: Velocity, Surface Area
Secondarily experiment: change of surface material: rubber/felt
Apparatus:
List of equipments
Surface (table)
Block
Computer
Dual Force Sensor
Masses
Procedure:
We attached the block to the Dual Force Sensor and started pulling it with our hands at a constant speed. We executed the process by adding different weights on the velcro sided block to see how it would affect the force of friction between the table and the material. The Dual Force Sensor measured the amount of Ff, while the weights determined the Fn. Because it is being pulled at a constant speed, the Ff and Fnno Ff and the pulling force are equal are equal. The powers of the machine have to be equal because the block is moving at a constant speed.We changed the material of the block by experimenting once with velcro and once with the rubber side. We repeated the procedure the second time, but changed the side of the block so it was the table against the rubber surface.
Data Table
Velcro:
Fn (Newtons) Ff (Newtons)
0.64 N 0.16 N
1.13 N 0.24 N
1.62 N 0.36 N
2.60 N 0.45 N
5.54 N 0.86 N
8.33 N 1.38 N
Rubber:
Fn (Newtons) Ff (Newtons)
0.64 N 0.46 N
1.13 N 0.68 N
1.62 N 0.76 N
2.60 N 1.19 N
5.54 N 2.78 N
8.33 N 4.29 N
VM: As the Fn increases, the Ff increases constantly. Normal force -is this stella's graph?
Data Table
Velcro:
Fn (Newtons) Ff (Newtons)
0.64 N 0.16 N
1.13 N 0.24 N
1.62 N 0.36 N
2.60 N 0.45 N
5.54 N 0.86 N
8.33 N 1.38 N
Rubber:
Fn (Newtons) Ff (Newtons)
0.64 N 0.46 N
1.13 N 0.68 N
1.62 N 0.76 N
2.60 N 1.19 N
5.54 N 2.78 N
8.33 N 4.29 N
MM: Ff=(0.2 N/N)xFn+0.07N
Slope: For every 1 Newton added to the normal force, the force of Friction increases by 0.2 N.
Y-int: When the Fn is at 0 Newtons, the Ff is at 0.07 N.
MM; Ff=(90.5 N/N)x Fn+0.02N why does it say 90.5?
Slope: For every 1 N added to the Fn, the Ff increases by 0.5N.
Y-int: When the Fn is at 0 N, the Ff is at 0.02N.
Experiment 2 Velocity
2. How does the velocity affect the Ff?
Prediction: As the velocity increases, the force of friction decreases.
IV: Velocity
DV: Ff
CV: Fn, Surface materials
Procedure
We pulled the block at different speeds: slow, medium, fast. We were able to measure the different velocities with the Dual Force Sensor, and determine the relationship between the velocity and Ff.
VM: As the different speeds are applied, the Force of friction remained the same.
Experiment 3 Surface Area on Ground
How does the surface area affect the Force of friction?
Prediction: The bigger the surface area, more Force of Friction is present.
IV: Surface Area
DV: Force of Friction
CV: Speed and Surface Material
Secondary Experiment: Change the side of the block.no secondary here -you changed the side of the block to manipulate the surface area
Procedure
We measured the Force of Friction using a piece of wood and used all the different sized surface areas. We made sure the the speed and the surfaces remained the same in order for our experiment to be as accurate as possible.
VM: The surface area does not affect the force of friction.
where is the graph from schoology?
Conclusions
Introductory Paragraph
Through these series of experiments, our goal was to determine the relationships between the surface area, velocity, and force of friction. We were able to find out that the only factors that have an affect on the friction is Fn and surface. Throughout the three experiments, we kept the surface constant in all three of the experiments. We changed the the Fn, velocity, and the surface area in order to find out how they affect the force of friction.
Experiment 1
According to our first experiment, all of the graphs are linear because of the same slope. The slopes are the same because the same surface was used. The velcro side was 0.2 N/N while the rubber side was 0.9 N/N. The slope of the velcro side was less, because there was less friction against the surfaces. By adding weights, it shifted the graphs but they still remained proportionally the same. The slope also remained the same. We concluded that as the Fn increases, so does the Ff.What is the equation? What do we call the slope?
Experiment 2 & 3
We were able to find out that the velocity and the surface do not have an affect on the Ff. The Ff will continue to remain the same if and only if the Fn and surface stay constant. The change in velocity or surface are do not affect the force of friction. My group predicted that the bigger the surface area, the bigger Ff would be. Our prediction was wrong, as we concluded that it does not affect the relationship whatsoever.
Drawing Conclusions
It is possible for two people wearing identical shoes to have different forces of friction. The material of the surface they are standing on and their Fn would be factors that could affect the Ff. The different surfaces could have affect the friction, based on whether the surfaces would have less or more friction. For example, tile floors would have less friction than carpet. The weights of the individuals also have an affect on the forces of friction. Based on our first experiment, it was proven that the more Fn applied, the more Ff would be present. If one of the people weighed more, that person would have more force of friction. The only way the forces of friction could be equal is if they both weigh the same and are standing on same surface material. The surface area and velocity would not change the force of friction.
Errors
For next time, we could be more careful and take more accurate data. An error that occurred during our experiment was when we failed to zero the program, resulting in data that was not accurate. If we knew what we did wrong during that time, we would have saved time and extra work. Thankfully we were able to fix the problem before it was too late.
Journal Statement
After completing the lab report, I felt more confident in my lab skills. I understood the concept and what we were trying to achieve in the experiment. Through this lab, I understood how to determine the relationship between 2 or more factors by changing variables and keeping one constant. In order to improve the experience, we could pay closer attention to what kinds of data we were collecting and ask questions if conflicts arose.good!
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