King of the Hill Lab

Key Question
The objective is to build a car that is self propelled and can make it over the hill.

Car plan and Justification
Materials list : 1 small mousetrap ($5), 1 piece of cardboard($0.25), 4 bottle caps($0.50), 1 skewer($0.05), duck tape($0.05), 1 pen(1$), string($1), 10 to 20 little rubber bands ($1)

The car will be light so that it can go faster it will also be propelled by a mouse trap because it creates a big force to propel the car. The rubber bands around the wheels will create a small amount of friction so that the plastic bottle caps aren't too slippery

 


The force that will act on our car is the force of the mouse trap. Since it is tied to the skewer the skewer will be pulled by the force of the mouse trap. The car will accelerate at the start of the race because it will go from stopped to speeding up then it will slow down as the force of the mouse trap is no longer there and it finishes going up hill. Our car is not that massive and weights very little which means it will have a higher velocity to balance out the force. Newtons first and third laws apply to this because the car continues to move after even after the force is applied also as the car accelerates the mouse trap is applying a lesser force whites decreasing. At the top of the hill the car will start to lose momentum and impulse.

Analysis
I am disappointed with my cars performance because I believe if we would have been able to test it more before the race we could have been able to fix the wheel better. I think we were just unlucky.


Ramp Test evaluation

• We did not make any modifications from our original plans.
• Our car had a big displacement. It came out quick with a lot of acceleration then started to slow down as it approached the top of the ramp.
• The car did not perform as expected due to the positioning of the wheels because it kept turning to the side. It did go a good see just right into the wall.
• The only modification is the replace the wheels so the car can go straight.

Evidence

Our car was not successful in the end. We could not get the wheels straight. The cars that were the most successful in this project were the ones that were more massive and had bigger mouse traps. Since the mass and the force were increased the time it took for the car to accelerate also increased which is a good strategy for a race like this because it needs enough time and force to get up the hill. It is also good for a car to be more massive because it can overpower smaller cars. I would improve by using a bigger mouse trap and making sure the wheels are straight. 

yes, being well constructed wins out over everything...  :)

Ticker Tape

Isabel Gonzalez
NG 1 - What is the relationship between position and time for a cart rolling down a ramp?
The time stays the same but the position increases because the cart is accelerating since there is no friction.

What is the relationship between velocity and time for a cart rolling down a ramp?
The time stays the same but the velocity increases proportionally. time stays the same??  what does that mean?

NG 2 - Investigating

First we set up the ramp at an angle by propping it up with 2 boxes. Next we set up a 60 Hz ticker timer using carbon paper. We taped the end of the carbon paper to the cart and placed it at the top of the ramp. We then let the cart go after turing on the ticker timer. The ticker timer made a motion map and I used that to calculate the time and position. Every six dots, which was 0.1 seconds, I calculated the position using a meter stick.

Table  
variable names?
0s   - 0cm

0.1s - 1.5cm
0.2s - 5cm
0.3s - 10.4cm
0.4s - 17.5cm
0.5s - 26.4cm
0.6s - 37cm
0.7s - 49.4cm
0.8s - 63.2cm
0.9s -79.4 cm

I cut my ticker tape every 6 dots because that counted as 0.1s then pasted it on the graph to show how the velocity changed every 0.1s

NG 3
Position Graph  I can't see this??

Verbal Model: As the time increases, the position increases increasingly
Math Model: x = (88.485 cm/s^2) t^2

Velocity Graph 

(I can't figure out how to rotate the pic)

VM: As the time increases the velocity increases proportionally.
MM: y = mx +b
         Vf =at + Vi
                 ^
slope =   (cm/s)/s = cm/s^2 what does the slope mean?
y-intercept?
DeltaX = 1/2 at^2

NG 4
The displacement is the area under the velocity graph. When plugging the slope of X and V into a chart we found that X is equal to 1/2 V so we replaced it with the variable a because it is the acceleration and t always stays the same. Therefore to find the change in position you use DeltaX=1/2at^2 equation.
The second equation is saying that the final velocity is equal to the initial velocity plus the acceleration. We know that a is equal to the slope of V and the units are equal to the change in y over the change in x. That simplifies to (cm/s)/s= cm/s^2. Every second of time (s^2) the velocity (cm/s) changes.

NG 5 
Each experiment didn't have the same numbers for the constant slopes because it all depended on the angle of the ramp. Some were higher and others were lower. One error could have been the measurements of the position on the ticker tape. Since I used a meter stick it is hard to make it exact. Something else I would like to test is my acceleration when I am running. It would be cool to race other people and see who had a greater acceleration and try to prove it. good ideas!

Marshmallow Shooter

Experiment 1

NG1 How far will the marshmallow travel using different length tubes?

NG2 Procedure: We cut the folders and rolled them up at different lengths . The shortest is 9 inches, then 12 inches, and the longest was 18 inches. We placed the marshmallow closest to the mouth in the tube so that it starts the same place every time. We had the same person blow and used the same marshmallow every time. We estimated where the marshmallows landed and used meter sticks to see how far it went.

NG3
IV: Length of the tube

DV: How far the marshmallow travels

CV: Same person shooting and how hard she blows

NG3 Data Table:

Tube Length        Distance

  9 in.       ----        99.6 in.

  12 in.     ----        125 in.

  18 in.     ----        137 in.

When the tube length increases the distance increases.

The longer the tube the more time you blow with the same force. When there is more time there is more velocity meaning more momentum because J = ΔP and J = F x T.

Experiment 2

NG1 Will the mass of the marshmallow affect how far they travel?

NG2 Procedure: We kept out the meter sticks in line to tell how far the marshmallows travel. Next we got 6 marshmallows. We taped 3 marshmallows together with scotch tape in a line. Next we taped 2 marshmallows with the same tape and finally we taped 1 marshmallow the same so that it would have the same friction as the rest of them. good!! We kept the starting point, shooter, and tube the same. Each time we estimated where the marshmallow landed.

NG 3 

IV: Mass of the marshmallow

DV: How far the marshmallows travel

CV: Same person shooting and how hard she blows

NG 3 Data Table:

      Mass              Distance

1 marshmallow -- 185.5 in.

2 marshmallows -- 89 in.

3 marshmallows -- 71 in.

When the mass increases the distance decreases.

Force*Time=mass*velocity 

B force x C Time = 3 marshmallows x lower velocity 

B Force x C Time = 1 marshmallow x higher velocity 

good!

Experiment 3

NG1 How far will the marshmallow travel when starting at different heights?

NG 2 Procedure: 
We used the same shooter, 12in. tube, force and marshmallow. First the shooter stood on a chair, then on her feet, and finally on her knees. We did 2 trials of each by estimating where they landed and then took the average and used one number.

IV: Height of the starting point

DV: How far the marshmallows travel

CV: Same person shooting and how hard she blows

NG3 Data Table:

    Height             Distance

Chair(80 in.) ---     91 in.

Standing(60 in.)--- 82 in.

Knees (34 in.) ---  74.5in.

When the height increases the distance increase.
Speed is the same but the time to fall is different. The higher the longer time to fall.

NG4-5
From these experiments we have now proved that J=ΔP (impulse = momentum). This is because J= F x T (impulse = force x time) and F x T = M x ΔV (Force x time = mass x change in velocity).
This is proved by our first experiment. The force stayed the same but the amount of time increased which means increase velocity and also momentum. For example, with the 9 in. tube, the marshmallow will have the same force applied as the rest but for not as long since it is shorter. This means there is less momentum therefore it the marshmallow won't travel as far. The longer the tube the more time the same amount of force is applied on the marshmallow. 
In our second experiment we noticed that as the mass increases the distance the marshmallow travels decreases. This is true because since the force and time are equal to mass and velocity when one goes up the other gets lower. When there is one marshmallow the velocity increases because it is equal to the impulse that is given to all of the other different marshmallow masses. When the marshmallow mass increases the velocity decreases because it is still equal to the same impulse. good!
In our third experiment we learned something different. The force, and time mass, and velocity stay the same but the height of the marshmallow increases. The higher the marshmallow starts, the amount of time the marshmallow has to fall increases. When the height increases the distance increases.

Error analysis
In our experiments there are many things that we could have done better on. Something we could have done to improve was to get a machine like a fan to blow out the marshmallow so that the same amount of force would be applied more precisely. We could have also recorded all of the trials to try to get a better estimate of where the marshmallow landed each time. what do you mean all of the trials?

Friction Lab

Experiment 1

Pre-Lab notes
Key questions?
IV: Fn  
DV:  Ff
CV:  Surface

How is the friction force affected when the surfaces are pressed together harder?
Prediction: The friction force increases where there is more weight and the surfaces are pressed together harder

How does the material of the surface affect the friction?
Prediction: Some materials are bumpier which causes more friction and when they aren't as bumpy there is less friction because things aren't getting caught on each other

Apparatus: Dual-range Force Sensor, block with different material on each surface, lab quest mini, and weights

Procedure:
Trial 1:
1) Get materials
2) use logger pro
3)test the felt side of the block with no weight by pulling it on a flat surface at a constant speed.test by doing what exactly?  If this is all I saw I would have no idea what to do....
4) test with added weight  and take what data?  from where?  can you see that if this is all I saw then I would not know what to do?

Trail 2:
1)test the rubber side of the block with no weight
2) Add weight

Data set 1 (weight of block 65g)
felt side
Fn(N)                     Ff(N)
0.637N                 0.17N
1.127N                0.285N
1.617N                0.375N
2.597N                0.533N
5.537N                1.444N

VM: As more mass is added the normal force increases, this makes the force of friction increase
MM: Ff=(0.260n/n)Fn - 0.03N
Slope: For every 1N of the Fn, the friction increases by 0.260N
Y-int: When the normal force is 0, the force of friction is -0.03


Data set 2
rubber side
Fn(N)                  Ff(N)
0.0637N             0.789N
1.127N               1.269N
1.617N               1.734N
2.597N               2.531N
5.537N               6.136N


VM: As the masses increase the normal force increases, this also makes the force of friction increase
MM: Ff = (1.09n/n)Fn - 0.02N
Slope: For every  1N from Fn, the friction increases by 1.09N
Y-int: When the normal force is 0N, the force of friction -0.02N is....
Mu - coefficient of friction
Ff=(1.3n/n)Fn
Ff= MuFn

                            Affects Ff

• materials
• how hard surfaces press together 

Experiment #2
Velocity
IV: velocity
DV: Ff
CV: Fn (mass) surfaces

Purpose Question
How does the velocity  affect the Ff?
I will change the velocity of the block by pulling it at different speeds. Then I will measure the Ff and see the relation.

Procedure
We will change the speeds of the block to measure if that is what affects the force of friction. We will keep the surfaces we use the same and pull the block at a constant speed.

Trial 1
  V          Ff
Slow     .74N
Med      .80N
Fast       .84N

No relationship and no effect
b/n Ff velocity

Experiment 3
surface area

Procedure
Get the block of wood that you can change the surface area. Pull the block of wood at a constant speed. Then test the force of friction.
IV: surface area
DV: Ff
CV: Speed , surface materials

The surface area does not affect the force of friction.

We are trying to find out what affects the force of friction? Is it the weight added to a surface, velocity, or the surface area? To figure out if it was the surface we tested for the force of friction we kept everything the same but changed the type of surface. To figure out if it was the velocity we kept everything the same except the speed she pulled the block at. To find out if it was the surface area we kept everything the same but changed the side she pulled the block on.

The slopes of the equations are different because it depends on the friction of every surface. The y intercepts are also similar because they are close to zero because they are not moving at the y intercept. The slope of the equation is telling us the force of friction between the surfaces when there is weight added on the surfaces. The equation for the calculation for force of friction is Ff= MuFn not 1.3...  the generic mu in the main equation...  this paragraph somewhat confusing.,.,..that's it for the rewrite??  I said the paragraph was confusing....??

In experiments 2 and 3 the graphs tell me that the the force of friction was not affected. In these experiments we tested if the velocity and surface area would affect the force of friction but they did not because the graphs tell us the force of friction stays the same the whole time.

It is possible for 2 different people wearing the same shoes to have different forces of friction. If the people weight differently that will affect the friction because that means that persons shoes press harder on the floor so those surfaces will get caught on each other even more. yesIt is also possible for two people wearing different shoes to have the same force of friction because it depends on the amount of weight added to the surfaces and the material of the shoes could be the same.more specifically what.,.,.?

One error could be that we weren't always pulling the block at a constant speed. Another error could be that the surfaces were not always the same the whole experiment like if one part of the table had more friction than the other.

Gravity Lab

Data Analysis: labels and units!

0.06kg            0.589

0.07kg            0.681 

0.08kg            0.786 

0.09kg            0.891 

0.1kg              0.997

VM: As the weight  mass increases, the force increases.

MM: Fg = (10.26N/Kg)mass-0.0032N

Slope: For every 1 Kg added, the force increases by 10.26 N.

Y-int: Where the mass is zero Kg, the force is -0.0032N

(the y-int should be 0 because if there is nothing hanging there would be no force)

Claims/Evidence/Conclusion

Mass and weight are both different. Mass is the measure of matter in an object while weight is the measure of how hard gravity is pulling an object. Everyones graph is the same becasue the amount strength of the field of gravity on an object is ALWAYAS the same and they are all linear.. Our graph is a bit different from others because we had different masses but everyone has similar slopes. Fg=mg means that the force is equal to mass x gravity. It gives you the amount of pull on the mass due to gravity.all points are there....  but conclusion could be better written, clearer, and proofread it!

Dueling Buggy Lab

- Objective:  The objective was to figure out the point that the two buggies would meet going in opposite directions. 

- Your Plan- : We laid out 3 meter sticks and marked every 2 feet with a piece of tape. We took a video of each buggy and with that we found the exact time it took for them to travel every 2 feet and a time it took to travel a total of 10 feet. 

-Data Analysis:  After we collected the data for both cars we then calculated the speed measured in feet per seconds for each. HOW did you get these speeds? Once we got the speed we created a y=mx+b equation. M= their speed, b= their starting position, x= their time, and y= their position. good!For the fast buggy we got y=1.37x and the slow buggy was y=-.5x+10. We graphed these equations using a calculator and found the point of intersection: 7.33 feet and 5.35 seconds. We tested it out and it was right. where is the graph?

-Using your Model/Designing a Solution:  When asked where they would intersect starting at 4 feet, we plugged 4 in for 10 in the equation for the slow buggy because that would be the new starting point. After graphing with a calculator we concluded that the intersection would be at 3 feet in around  2.13 seconds. Once we tested it out our predictions were correct. 

Buggy Lab

Pre-Lab observations

-Stays in a straight line
-moves
-noise
-has head lights and antenna
-wheels
-red
-forward only
-keeps going
-two seats

 

Objective
What is the relationship between it's position and time?

The Plan
For both our trials we will start the buggy at zero and time how long it takes for it to move 20 inches constantly.add a bit more - how will you time it?  who will do what job?

Data Analysis 

-Trial 1 

why so many decimal places?

-Trial 2

Data Graph

VM - As the position increases, the time increases proportionally
MM -  Position = (20.8 in/sec) time + -20.8in
Slope - For every second, the position increases 20 inches
Y-int - The the amount of seconds equal zero the position is -20.8 inches

 

VM - As the time increases, the position increases consistently 

MM - Position = (19.7 in/sec) time+ -9.5 in

Slope - For every second,  the position increases 10 inches  why 10?  isn't it 19.7?  or 20 if you round?

Y-int- The amount of seconds equal zero the position is -9.5 inches    

Conclusion
In each of the experiments the buggy was moving in either a positive  direction position or a negative position, this made the slope positive or negative. All of the buggy's move at a constant speed so all the experiments have a linear trend. Since all of the buggy's speeds are similar, all graphs have a similar slope. Even though they have similar slopes they each have a different starting position so each graph has a different y-intercept.nice!
In our experiment we had a few errors. Our reaction time for the timer was not completely accurate. Also our marks for when to stop the timer differed slightly each time. A better way to have gotten our data would be to take a video of the buggy moving next to the meter sticks and to pause the video to time the Buggy at a more accurate mark.great idea!!

Journal Statement 

I liked this experiment because it was a good one to start the year off with so that we could get used to how to do these lab blogs. good!