I was absent the class before this so I didn't get that packet.
Tuesday, November 25, 2014
Friday, November 14, 2014
Friction Lab
1. Surfaces pressed together
-Question: When the surfaces are pressed together harder, how does that affect the force of friction?
-Variables: Independent Variable- normal force
Dependent Variable- Friction
Controlled Variable: Velocity and surface and block?
-Prediction: I predict that when the objects are pressed harder together, the force of friction will increase.
-Apparatus: Block (rubber or Velcro)
Masses (Weight)
Machine that measures force (Ft)
Table (Fn)
Computer
-Procedure: Attach the block to the machine that measures force and start moving it at a constant speed. Then you start adding weight to the top of the block and move it at a constant speed. You do this again with even more weight added. Then you do this whole experiment over but do it on the other side of the block. All together you would do the experiment twice, once with the velcro and once with the rubber. You can tell the machine measures the force of friction because the force of friction and the power of the machine have to be equal because the block is moving at a constant speed. By adding weight you can tell the Fn because the weight you added equals the force of Fn because they are equal because it is not moving up nor down.
-Procedure: Attach the block to the machine that measures force and start moving it at a constant speed. Then you start adding weight to the top of the block and move it at a constant speed. You do this again with even more weight added. Then you do this whole experiment over but do it on the other side of the block. All together you would do the experiment twice, once with the velcro and once with the rubber. You can tell the machine measures the force of friction because the force of friction and the power of the machine have to be equal because the block is moving at a constant speed. By adding weight you can tell the Fn because the weight you added equals the force of Fn because they are equal because it is not moving up nor down.
DATA TABLE:
Velcro:NORMAL force
Natural Force (Newtons) Force of Friction (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:
Natural Force (Newtons) Force of Friction (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
-Verbal Model: As the normal force increases, the force of friction increases proportionally.
-Math Model: Ff = (0.2 N/N) x Fn + 0.07 N
-Slope: For every one Newton added to the normal force, the force of friction increases by 0.2 Newtons.
-Y-Intercept: When the normal force is at 0 Newtons, the force of friction is at 0.07 Newtons.
-Verbal Model: As the normal force increases, the force of friction increases proportionally.
-Math Model: Ff = (0.5 N/N) x Fn + 0.02 N
-Slope: For every one Newton added to the normal force, the force of friction increases by 0.5 Newtons.
-Y-Intercept: When the normal force is at 0 Newtons, the force of friction is at 0.02 Newtons.
2. Velocity
-Question: How does the velocity affect the force of friction?
-Variables: Independent Variable: Velocity
Dependent Variable: Friction
Controlled Variable: Velocity the velocity can't be a controlled variable if it is one that you are testing. Controls are things that do not change in the experiment.
-Prediction: I predict that the faster the object is moving, the friction will be the same because the Fn is still constant.
-Procedure: Change the velocity of the block and pull it at different speeds. Then measure force of friction and see the relationship while using the same Fn and surface.
-Force of Friction vs. Velocity: We found out that the velocity does not affect the force of friction.
3. Surface area on ground
-Variables: Independent Variable: Velocity
Dependent Variable: Friction
Controlled Variable: Velocity the velocity can't be a controlled variable if it is one that you are testing. Controls are things that do not change in the experiment.
-Prediction: I predict that the faster the object is moving, the friction will be the same because the Fn is still constant.
-Procedure: Change the velocity of the block and pull it at different speeds. Then measure force of friction and see the relationship while using the same Fn and surface.
-Force of Friction vs. Velocity: We found out that the velocity does not affect the force of friction.
3. Surface area on ground
- Question: How does the surface area affect the force of friction?
-Variables: Independent Variable: Surface Area
Dependent Variable: Force of Friction
Constant Variable: Speed and Surface Materials
-Prediction: The larger the surface area is, the more friction there will be.
-Procedure: Measure the force of friction while using a piece of wood and using all the different sides to enable us to change the surface area. While the surface area is changing, the speed and surfaces still have to remain constant throughout the experiment.
-Surface Area vs. Force of Friction: The surface area does not affect the force of friction.
where is the graph I made for you?
Conclusion
-Introductory Paragraph: By doing these three experiments, we were trying to find out how the Fn, velocity, and surface area effects the force of friction. We found out that the only thing that effects the force of friction is the change in Fn and the surface. For all three experiments we kept the surface constant. In experiment one we changed the Fn, experiment two we changed the velocity, and in experiment three we changed the surface area and found out Fn was the only variable that changed the force of friction.
-Experiment One: All the graphs using the same surface are linear. When the surfaces are not pushed together there will be no force. The slopes are the same because the slope describes the type of surface and we all used the same surface. The slope for the velcro side was 0.2 N/N and the slope for the rubber side was 0.9 N/N. The slope for the velcro was less than the rubber side because velcro has less friction than rubber. The larger the slope, the more force of friction there is. The general weight of the block that was used was 65 grams. Since that was a general weight, it might have affected some of the graphs slightly, but the slopes were generally still the same.what is the slope called? what is the equation?
-Experiment Two and Three: For graphs for experiments two and three show that the velocity and surface are does not affect the force of friction. The force of friction will always remain the same if the Fn and surface remain constant even if the velocity or surface area changes. I predicted that the velocity would not effect the force of friction but the surface area would. I was correct about the velocity but wrong about the surface area. I thought since more area is touching the other surface, I thought that would increase the amount of friction.
-Drawing Conclusions: It is possible for two people wearing identical shoes to have different forces of friction because of the surface they are standing on and/or how much they weigh. One person could be standing on carpet and the other one could be standing on hardwood, which would effect the force of friction because the surfaces they are standing on are completely different. The weight could also change the amount of friction. This is like the experiment where the Fn was changed. Because the weight of the person is heavier, that causes more Fn since the force of gravity and the normal force are equal. The higher the Fn, the more friction there will be. yes....Two people have different types of shoes could have the same amount of friction because the the Fn could be equal and from the experiment about surface area, how would that make the same friction force then?we learned that surface area does not effect the amount of friction. In summary, the amount of friction force is caused by the amount of normal force and kinds of surfaces while the surface area does not affect the amount of friction force.
-Errors: Two sources of error that occurred during this experiment were that we forgot to zero the machine that measures the force of friction and in the first experiment when we were supposed to move the object at a constant speed. We could fix this by remembering to zero the machine and have something that moves at a constant speed drag it. Finding how the slope of the surface affects the friction would be interesting to learn.
-Journal Statement: I feel like I am getting better at lab reports because I feel like I know what information to put in and what the important information is. To improve my writing we could go over what should be in each part again.true, good job!
-Variables: Independent Variable: Surface Area
Dependent Variable: Force of Friction
Constant Variable: Speed and Surface Materials
-Prediction: The larger the surface area is, the more friction there will be.
-Procedure: Measure the force of friction while using a piece of wood and using all the different sides to enable us to change the surface area. While the surface area is changing, the speed and surfaces still have to remain constant throughout the experiment.
-Surface Area vs. Force of Friction: The surface area does not affect the force of friction.
where is the graph I made for you?
Conclusion
-Introductory Paragraph: By doing these three experiments, we were trying to find out how the Fn, velocity, and surface area effects the force of friction. We found out that the only thing that effects the force of friction is the change in Fn and the surface. For all three experiments we kept the surface constant. In experiment one we changed the Fn, experiment two we changed the velocity, and in experiment three we changed the surface area and found out Fn was the only variable that changed the force of friction.
-Experiment One: All the graphs using the same surface are linear. When the surfaces are not pushed together there will be no force. The slopes are the same because the slope describes the type of surface and we all used the same surface. The slope for the velcro side was 0.2 N/N and the slope for the rubber side was 0.9 N/N. The slope for the velcro was less than the rubber side because velcro has less friction than rubber. The larger the slope, the more force of friction there is. The general weight of the block that was used was 65 grams. Since that was a general weight, it might have affected some of the graphs slightly, but the slopes were generally still the same.what is the slope called? what is the equation?
-Experiment Two and Three: For graphs for experiments two and three show that the velocity and surface are does not affect the force of friction. The force of friction will always remain the same if the Fn and surface remain constant even if the velocity or surface area changes. I predicted that the velocity would not effect the force of friction but the surface area would. I was correct about the velocity but wrong about the surface area. I thought since more area is touching the other surface, I thought that would increase the amount of friction.
-Drawing Conclusions: It is possible for two people wearing identical shoes to have different forces of friction because of the surface they are standing on and/or how much they weigh. One person could be standing on carpet and the other one could be standing on hardwood, which would effect the force of friction because the surfaces they are standing on are completely different. The weight could also change the amount of friction. This is like the experiment where the Fn was changed. Because the weight of the person is heavier, that causes more Fn since the force of gravity and the normal force are equal. The higher the Fn, the more friction there will be. yes....Two people have different types of shoes could have the same amount of friction because the the Fn could be equal and from the experiment about surface area, how would that make the same friction force then?we learned that surface area does not effect the amount of friction. In summary, the amount of friction force is caused by the amount of normal force and kinds of surfaces while the surface area does not affect the amount of friction force.
-Errors: Two sources of error that occurred during this experiment were that we forgot to zero the machine that measures the force of friction and in the first experiment when we were supposed to move the object at a constant speed. We could fix this by remembering to zero the machine and have something that moves at a constant speed drag it. Finding how the slope of the surface affects the friction would be interesting to learn.
-Journal Statement: I feel like I am getting better at lab reports because I feel like I know what information to put in and what the important information is. To improve my writing we could go over what should be in each part again.true, good job!
Saturday, October 25, 2014
Force of Gravity
Data:
Mass (kg) Force (N)
0.06 kg 0.58 N
0.1 kg 0.97 N
0.15 kg 1.47 N
0.25 kg 2.46 N
0.55 kg 5.342 N
graph backward - Force vs, mass, force on y axis! Did you not look at all of the whiteboards and see yours is backward?
Data Analysis:
Verbal Model: As the mass increases, the force increases proportionally.
Math Model: Force = (9.7045 N/kg) x Mass + 0.0122 N yes but this does not match your graph
Fg = mg
Slope: For every one kilogram the mass increases, the force of gravity increases by 9.7045 N.
Y-Intercept: When the mass is zero, the force is 0.0122 N. The y-intercept should be zero because there is no force added at this time because their is no mass attached.
Conclusion:
Claims and Evidence: All the graphs are linear and with a positive slope. The slope (or N/kg) of about 9.8 is going to be the same with everyone because we all did this experiment on Earth, so we all had the same gravitational field. Because the gravitational field is the same, the amount of force per kilogram will remain constant. good! Mass and weight are different because mass is the total amount of stuff the item is made out of and the weight is how much the stuff the item is made out of weighs in total .... no - weight is the force, the pull from the Earth. The amount of force is another way of describing how much the item "weighs." The more mass an object has, the amount of force or "weight" increases. Every item has the same gravitational field even if their masses differ. The amount of Newtons per kilogram multiplied by the amount of mass gives you the amount of force the object will have. This is represented in the equation Fg = mg. good
Mass (kg) Force (N)
0.06 kg 0.58 N
0.1 kg 0.97 N
0.15 kg 1.47 N
0.25 kg 2.46 N
0.55 kg 5.342 N
graph backward - Force vs, mass, force on y axis! Did you not look at all of the whiteboards and see yours is backward?
Data Analysis:
Verbal Model: As the mass increases, the force increases proportionally.
Math Model: Force = (9.7045 N/kg) x Mass + 0.0122 N yes but this does not match your graph
Fg = mg
Slope: For every one kilogram the mass increases, the force of gravity increases by 9.7045 N.
Y-Intercept: When the mass is zero, the force is 0.0122 N. The y-intercept should be zero because there is no force added at this time because their is no mass attached.
Conclusion:
Claims and Evidence: All the graphs are linear and with a positive slope. The slope (or N/kg) of about 9.8 is going to be the same with everyone because we all did this experiment on Earth, so we all had the same gravitational field. Because the gravitational field is the same, the amount of force per kilogram will remain constant. good! Mass and weight are different because mass is the total amount of stuff the item is made out of and the weight is how much the stuff the item is made out of weighs in total .... no - weight is the force, the pull from the Earth. The amount of force is another way of describing how much the item "weighs." The more mass an object has, the amount of force or "weight" increases. Every item has the same gravitational field even if their masses differ. The amount of Newtons per kilogram multiplied by the amount of mass gives you the amount of force the object will have. This is represented in the equation Fg = mg. good
Friday, October 3, 2014
Dueling Buggies Lab
Objective:
To know the position (cm) of where the two buggies will meet with the buggies traveling in opposite directions, moving at different speeds and with a certain distance in between them at their starting positions. Also how long it will take the two buggies to meet (sec).
Plan:
Plan:
- For the fast buggy, my group measured how long it took the buggy in seconds to get from the position of 0 cm to the position of 80 cm. It took the buggy 1.57 seconds to travel this distance(0 cm-80 cm.) With this information we were able to find out that the buggy travels at the speed of about 51 cm/sec by dividing 1.57 seconds by 80 centimeters. other way - you are dividing 80 cm by 1.57 sec
- For the slow buggy, my group measured how long it took the buggy in seconds to get from the position of 0 cm to 80 cm. It took the buggy 3.88 seconds to travel this distance(0 cm-80 cm.) With this information we were able to find out that the buggy travels at the speed of about 20 cm/sec by dividing 3.88 seconds by 80 centimeters.
Data Analysis:
- After collecting the data for the two buggies we made an equation that would tell us at what position, in centimeters, the buggies would meet if we plugged in the distance between the starting positions or otherwise known as the total distance traveled by both buggies. Our equation stated that the whole distance (cm) traveled by both buggies equals the amount of centimeters traveled per second of one buggy multiplied by the amount of time (sec) the buggy traveled added together with the other buggy's centimeters traveled per second multiplied my the amount of time (sec). The time plugged in for both buggies would always be the same for both because they traveled for the same amount of time. We added them together instead of subtracting because the distance traveled per second multiplied by how long it travels for represents the total distance traveled by that one buggy, so to find the total distance of both you would have to do that step with both and add them together to give you the total distance traveled by both instead of just one. excellent!!
- f(d)=20t+51t
Using your Model/Designing a Solution:
- My group predicted that if the total distance between the buggies starting positions was 170 cm then the buggies would meet when the fast buggy reached the position of 121.89 cm and the slow buggy reached the position of 48.11 cm. To reach these positions it would take the buggies about 2.39 seconds. Our equation did work and we did not find out that our data or method was wrong.
Friday, September 12, 2014
Buggy Lab
Pre-Lab Observations:
Conclusion:
Claims and Evidence: The sign of the slope tells whether the buggy moved in a positive or negative direction. Since all buggy's are similar and have a constant speed, the slope should be linear and similar. If the slope is positive than that shows that the buggy moved in a positive direction, but if the slope is negative than the buggy moved in a negative direction. Since the buggys started at different starting points, they all have different y-intercepts.
Errors and Improve/expand: For trial two, my group kept the ending distance constant instead of keeping the starting distance constant. Also human reaction could have messed up the data a little bit because we may not have stopped the time at the right time. how could you fix this?
Journal Statement:
I liked this lab because I thought it was interesting learning the different vocabulary we are supposed to use and how everyone's graph and information was similar even though we tested in different ways. good!
- Stays in a straight line
- Moves
- Noise
- Has lights (headlights and antenna)
- Flowers
- Wheels
- Red
- Only goes forward
- Keeps going
- Two seats
Objective:
To find the relationship between the position and time of the buggy.
Trial 1:
Position: units Time:
-30 to -20 .8 seconds
-30 to -10 1.53 seconds
-30 to 0 2.13 seconds
-30 to 10 2.87 seconds
-30 to 20 3.58 seconds
Y=MX+B
Y=14.5x-31.6
We started the buggy at the position of -30 and changed the position of where the buggy stopped. We timed how long it took to get to the position in seconds. is this the plan? should come before the data
Verbal Model: As the time increases, the position increases proportionally.
Math Model: Position = (14.5in/sec)time-31.6inches
Slope: For every one second the time increases the buggy's position increases by 14.5 inches
Y-intercept: -31.6 inches is the initial position of the buggy
Trial 2:
Position: units Time:
-15 to 30 2.4 seconds
-25 to 30 3.51 seconds
-35 to 30 3.9 seconds
-45 to 30 4.7 seconds
-55 to 30 5 seconds
Y=MX+B
Y=-15.03X+23.64
We started the buggy at different positions and kept the stopping position constant at 30. We timed how long it took the buggy to get to the new position.
this analysis does not match the graph??
Verbal Model: As the time increases, the position increases proportionally.
Math Model: Position = (-14.5in/sec)time-31.6inches
Slope: For every one second the time increases the buggy's position increases by 14.5 inches
Y-intercept: -31.6 the initial position of the buggy
Trial 1:
Position: units Time:
-30 to -20 .8 seconds
-30 to -10 1.53 seconds
-30 to 0 2.13 seconds
-30 to 10 2.87 seconds
-30 to 20 3.58 seconds
Y=14.5x-31.6
We started the buggy at the position of -30 and changed the position of where the buggy stopped. We timed how long it took to get to the position in seconds. is this the plan? should come before the data
Verbal Model: As the time increases, the position increases proportionally.
Math Model: Position = (14.5in/sec)time-31.6inches
Slope: For every one second the time increases the buggy's position increases by 14.5 inches
Y-intercept: -31.6 inches is the initial position of the buggy
Trial 2:
Position: units Time:
-15 to 30 2.4 seconds
-25 to 30 3.51 seconds
-35 to 30 3.9 seconds
-45 to 30 4.7 seconds
-55 to 30 5 seconds
Y=MX+B
Y=-15.03X+23.64
We started the buggy at different positions and kept the stopping position constant at 30. We timed how long it took the buggy to get to the new position.
this analysis does not match the graph??
Verbal Model: As the time increases, the position increases proportionally.
Math Model: Position = (-14.5in/sec)time-31.6inches
Slope: For every one second the time increases the buggy's position increases by 14.5 inches
Y-intercept: -31.6 the initial position of the buggy
Conclusion:
Claims and Evidence: The sign of the slope tells whether the buggy moved in a positive or negative direction. Since all buggy's are similar and have a constant speed, the slope should be linear and similar. If the slope is positive than that shows that the buggy moved in a positive direction, but if the slope is negative than the buggy moved in a negative direction. Since the buggys started at different starting points, they all have different y-intercepts.
Errors and Improve/expand: For trial two, my group kept the ending distance constant instead of keeping the starting distance constant. Also human reaction could have messed up the data a little bit because we may not have stopped the time at the right time. how could you fix this?
Journal Statement:
I liked this lab because I thought it was interesting learning the different vocabulary we are supposed to use and how everyone's graph and information was similar even though we tested in different ways. good!
Wednesday, August 27, 2014
Earth-Moon Lab
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I can't see the picture... please try again and email me when it's done. Description looks good though!
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