King of the Hill

Key Question:

What was the objective? What were you trying to accomplish? 
-The objective was to make a self-propelled car that would effectively travel up the ramp and stop the opposing car from getting over. I was trying to accomplish stopping the other opponent by making a car that would be built well enough with enough force to make it over the ramp and stop the opponent.

Investigating:

Plan:
We are planning to make our car frame out of lightweight wood and to use CDs as the wheels. We will use a mouse trap for the force to make the car accelerate up the hill. We will attach a string to the mouse trap and wrap the other end around the wooden dowel attached to the back wheel. When the mouse trap pulls on the string, the string will spin the dowel forcing the wheels to move.





Materials: 
- 4 CDs (free from house)
-1 mouse trap ($1.00)
-rubber bands ($2.00)
-wooden dowels ($3.00)
-eye hooks ($4.00)
-balloons ($1.50)
-string (free from house)

Analysis: 

First Race: We won our first race, but barely. Our car was slower up the hill so the other car made it up first, but our car knocked it back down. whew!I was nervous because we almost lost, but excited that we won. I knew it was going to be a close race from the beginning because our cars were built very similar.

Second Race: Going into the second race, I was not expecting to win considering the outcome of our first race. The opponent's car was much bigger and looked a lot stronger than ours, so I wasn't surprised by the outcome, of us losing. I wasn't that disappointed because we made it into the second round and already won one race.

Developing a Model: 

We made our car lightweight and quick, that would still be able to take a hit. We made our car out of a mousetrap, CDs, and wood dowels. We used a mouse trap as the force to move the car and attached a string from the mouse trap to the wooden dowel that controlled the back wheels. This way the mouse trap forced the string to unravel, spinning the wheels. We also used metal eye hooks to connect the mouse trap to the wooden dowels and used balloons to cause friction with the ramp. The value of the force will cause our car to accelerate so it will go from moving at a constant speed to speeding up.

Evidence:

Our car didn't make it past the second round. Our car just wasn't built strong enough to beat the other car made out of wood. It could run good and make it up the hill, without the other opponent pushing it down. The force of the other car out pushed the force of our car making the net force/ acceleration towards ours, bringing us back down the hill. 
     Most of the winning cars were made out of wood. These cars were able to propel themselves up the hill and take hits from the other cars without any damage. The wood made them able to withstand the impact but also go at a good speed which the other car was also moving in. I think a successful car needed stability and speed.
     If I could change my car I would add more weight and distribute it properly. I think our car was too light so the heavier cars just pushed it around. I would make it out of a different material, such as wood to make it more durable. 

good work!

Ticker Tapes

Key Question: What is the relationship between position and time for a cart rolling down a ramp? What is the relationship between velocity and time for a cart rolling down a ramp?

Investigating:

                           

     

Explanation- The ticker timer uses a carbon fiber to show the change in velocity over time by creating ticks. The ticker timer makes 6 ticks per 1/10 of a second. We attached a piece of paper to the back of a cart and put the other end through the ticker timer so we can see the marks it makes and measure the velocity change in the cart as the time increases. The cart travels at a downward slope so it gradually speeds up. This is shown by the dots getting further and further apart since they are marked at even time intervals. Using the ticks, we were able to create data to turn into a graph. To make this data, we counted every 6 dots because that represents a tenth of a second. At every 6th dot we measured how far it is from the first dot. By doing that we were able to tell how far the cart traveled at every tenth of a second.  good

Data Analysis: 

Time (seconds)	Position (centimeters)
0.1 seconds	1.5 centimeters
0.2 seconds	4 centimeters
0.3 seconds	7.3 centimeters
0.4 seconds	11.5 centimeters
0.5 seconds	16.5 centimeters
0.6 seconds	22 centimeters
0.7 seconds	28.5 centimeters
0.8 seconds	35.5 centimeters
0.9 seconds	43.2 centimeters
1.0 seconds	52 centimeters
1.1 seconds	61.2 centimeters
1.2 seconds	71.5 centimeters
1.3 seconds	82.3 centimeters

Verbal Model: As the time increases, the position increases at an increasing rate. 

Math Model: x=(38cm/s^2)t^2 

Description: The cart is moving with an increasing velocity in a positive direction.

Velocity vs. Time Graph

Verbal Model: As the time increases, the velocity increases proportionally.
Math Model: Vf=at+Vi       

                        a=(cm/s)/s
Slope: Acceleration ((cm/s)/s or cm/s^2)
Y-Intercept: The initial velocity 

excellent
  Models:

• The new equation for the Position vs. Time graph is Δv x=(1/2)at^2. In this equation Δv  xis the area under the curve. This area represents the total distance traveled during the total amount of time. The new equation of the velocity graph is Vf=at+Vi. This is the derivative of the position graph and allows us to find the velocity equation. "a" represents acceleration, "t" represents time, "Vf" represents the final velocity and "Vi" represents the initial velocity. 

why is this font so weird??  and where did we get these equations - how do they relate to what you saw in lab?

Explaining: 

• No, the numbers for the constants and slopes were different for each group. This is because every group used a different ramp, so each group had a different incline. This causes the constants and slopes to be different because the car sped up at different rates, depending on the steepness of the incline.
• Errors in my experiment could have included using the dots either at the very beginning of the tape or at the very end. This could have messed up my data because during those times, the car wasn’t moving the way it was supposed to. We could have started the timer before we let the car go or stopped the timer after we already slowed down the car, messing up the distance between the dots, which shows how far the car traveled for that certain 
• Another idea to test regarding acceleration is the opposite of this. Instead of speeding up, what if the car was slowing down. Or another experiment could be to use the same ramp with the same incline but add weight to the car to test how weight affects the acceleration. both good ideas

Marshmallow Shooter

Experiment 1:

Key Question- How does the length of the tube affect the distance traveled by the marshmallow?

IV: Length of the tube
DV: Distance traveled
CV: How far from the ground and the force of the blow

Procedure-We will use three different tubes with the lengths of 29.5 cm, 25.4 cm and 12.7 cm. We will make a line of yard sticks on the ground on the centimeters side so we will be able to measure how far the marshmallow traveled. Our starting position will be at 0 cm. The marshmallow will be located on the side of the tube closest to the mouth and the other end of the tube will be located at 0 cm. The blow will be the same force each time. We will then measure how far the marshmallow traveled in centimeters. This experiment will be taken place three times for each of the three different tube lengths and find the average per size. excellent!

Analysis: 

Size of the tube (cm)        How far the marshmallow travelled (cm)
        29.5 cm                                           256.5 cm
        (large)                                             254 cm                                          
                                                                241.3 cm
                                                                Average: 250.6 cm

Size of the tube (cm)        How far the marshmallow travelled (cm)
        25.4 cm                                           157.5 cm
        (medium)                                        165.1 cm                                          
                                                                167.6 cm
                                                                Average: 163.4 cm

Size of the tube (cm)        How far the marshmallow travelled (cm)
        12.7 cm                                           94 cm
        (small)                                            101.6 cm                                          
                                                               106.7 cm
                                                                Average: 100.8 cm

The data shows that if the marshmallow is blown with an equal force, the marshmallow will travel further as the tube gets larger.
good
Experiment 2:

Key Question- How does the height of the tube from the ground affect how far the marshmallow travels?

IV: Height from ground
DV: Distance traveled
CV: Pressure of blow and length of tube

Procedure-  In our second experiment we will test how the height from the ground will affect the distance traveled by the marshmallow. We will start at 0 cm every time, keep the length of the tube the same and the force of the blow the same, and we will start with the marshmallow close to our mouths. We will collect three lengths for each height and find the average. The heights we will use are 5'2, 6'8 and 2'6.

Analysis: 

Height From Ground                                Distance Marshmallow Traveled
          5'2                                                                    132.08 cm
          6'8                                                                    162.56 cm
          2'6                                                                    48.26 cm

The data showed the higher the tube is from the ground, the further the marshmallow will travel.
good
Experiment 3: 

Key Question- How does the force of the blow affect how far the marshmallow travels?

IV: Force of the blow
DV: Distance traveled
CV: The height from the ground and the length of the tube

Procedure- In the third experiment, we will discover how the force of the blow affects the distance traveled by the marshmallow. We will start off at 0 cm each time with the marshmallow close to our mouth and the length and height of the tube will stay the same while the only thing changing will be the force of the blow. We used small, medium and large forces and tested each force three times and found the average.

Analysis:

Force of Blow                                         Distance Marshmallow Traveled
      Small                                                                    43.18 cm
      Medium                                                               132.08 cm
      Large                                                                   172.72 cm

verbal statement for this one??

Conclusion: 
             In the first experiment, we tested how the length of the tube affected the distance. This is another way of testing the time. We kept the marshmallow in the tube closest to our mouth. We made a conclusion that the longer the tube is, the further the marshmallow will travel because it will have a higher velocity. The velocity will grow with the length because it will have more time more time for what?. The more time it has the higher velocity it will have. This is proven in the equation J = Δp F x t= mΔv. We discovered that the higher velocity the marshmallow has, the further it will travel.              In the second experiment we tested how the height from the ground affected the distance the marshmallow traveled. The velocity, mass, force and time were the same with only the height changing. The higher the tube was, the further the marshmallow traveled. This is only because the marshmallow had more time in the air to travel, but it left the tube with the same velocity and momentum. It had more time in the air but the same amount of time with force applied to it, that is why the time in the equation is equal.       kind of, but seems confusing....  needs clarified      In the third experiment we tested how the force of the blow affects the distance the marshmallow traveled. We discovered that the greater force put on the marshmallow, the further it will travel. This is proven in the equation F x t= mΔv. The stronger the force, the higher the velocity and momentum causing the marshmallow to travel further.        Our experiments would have been more accurate if we had a machine that blew for us so we knew it was constant when it was supposed to be in experiments 1 and 2. Also if we could see exactly where the marshmallow landed our data would be more accurate. why couldn't you see exactly where it landed?  how could you fix that?

pretty good...  height needs explained a little more, and all could be clarified a bit...






                                                       
 

Forces Practice

I was absent the class before this so I didn't get that packet. 

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. 

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

DATA ANALYSIS:

         -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

    - 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!


    

  

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

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:

• 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.