Mouse Trap Car -Flora Lee

-Introduction

 We will make a Mouse Trap car which moves by the force of trap. When we put our hands off from the trap, thread which is connected to the trap will pull the wheel, then wheel will start to spin and finally the car will move.Through out the process of making car, we will learn what elements (such as friction, weight, size, the length of thread..etc).influence on the car's motion. By measuring the distance and time when Mouse Trap did work, we can calculate the velocity, acceleration and the force. Based on the data we got, we can critically think, what kind of law was applied in Mouse trap's motion and how we can make the car more fast or go farther distance.

-Ingredients
   Mouse Trap, Thread, Sticks, CDs for back wheels, Water bottle cap for front wheels, Fabric tapes, Wood pieces, Fire flame decoration tape, Tar for glue,  Card board for Body, Cute little Sponge Bob.
 -
Hypothesis
 Mouse Trap Car will go forward by the force of Mouse Trap as it flip back. And the car will keep moving froward after it ran out the force.

-Who, what, when, where you worked on the project.

Me, Flora Lee worked with my partner, You-shin Kim. On October 20, we had our first meeting to discuss and combine our idea. On Friday, October 21st we made a outline: what ingredients we will use, how we can get those, when, who will do what part of work. After we divied up the work, we started look for the ingredient from our enviornmnet to not use the store product as much as we can. And finally we begined to build a structure. Our house was in two different cities, so we tried to do most of work in school :during lunch, or in the morning, or after school. You-shin drew a draft and I cut and put pieces together and we tried again and again untill finding the greatest way,

-Your design successes and failure

 It was successful. We planed the ration of wheel and body, the structure of wheel and all car's design really thoroughly. And the outside design :adorable mini sponge bob driving the fire car was pretty creative because there was no group who decorated a car.

-Relevat things you discovered in the process of creating your design

  - We wrapped around the edge of CD by fabric tape, so it can make little bit of friction which will make wheels go straight forwards without sliding quppyly.
-We put the wood pieces between two CDs and attached together , so it can be really stable. Instead of using one thick wheel, we used two thin CDs with gap because thick one wheel make two much friction and it can be too heavy.
- We used appropriate length of thread because if is too long the mouse trap will not able to pull the thread well, and if it is too short, we will not able to use all force from mouse trap.
- We used really strong tar bond to attach wheels and central stick together, and when we attach thread and trap stick together. I thought it is really importand to make those stick well,  because if wheels and sttick does not spin smoothly and quickly at once, it will hamper the car's moving.
- We made the center stick smooth by using sand paper, so it can spin really flexibily.
- We made the wheel bigger than the body part, because if we give more weight to the wheel it will move better than make the big and heavy body with little wheel. If body is too big, it will make lots of friction.
- We made the car incline to the forward (higher back side. big wheel in the back and small whell  for front.) So the Mouse Trap Car's weight can contribute to pull the car to the front.

-How you chose to apply the various laws of physics were learning in ass right now.
I think, Newton's first law was applied. I could observe that Mouse Trap Car was still running after it ran out the force. This motion explained the inertia, characteristic of product which want to keep one's motion. So, the car stopped later even though the mouse trap fliped back before.

-Conclusion
Mouse Trap Car moved forward by using the force from mouse trap. Fliping of trap pulled the thread and it made the stick and wheels spin. After the mouse trap fliped back all the way, it still ran more distance because of the inertia according to Newton's first law.

-Data Chart

	Ist Run	2nd Run
Displacement(exhausted mousetrap)	4.2M	4.4M
Time (exhausted mousetrap)	4 sec	4.6 sec
Displacement (time)	10.3M	10.6M
Time (total)	12s	13.22s
Mass of car in Kg	0.212	0.212
Calculate Mad Velocity	4.8	5.55
Calculate Average Acceration	0.40	0.42
Calculate averafe deceleration	-0.11	-0.08
Calculate force and coefficient of friction	F= 0.023 mk=0.05	F= 0.017 mk=0.01
Calculate the spring’s applied force	0.085	0.089
Calculate work done	8.76	9.434
Calculate the power generated	1.9	2.1

Picture during the process. Kim has more pictures and video for our project.

Acceleration on an inclined Track

Acceleration on an Inclined Track

Flora Lee (with Amani Broyles and You-shin Kim)

Physics Block 2

Mr. Elwer

Introduction

-Background information

In Distance versus time graph, the slope means a velocity. And the Velocity versus time graph the slope means acceleration. So if the velocity and time graph increases in a straight line, it has a constant acceleration, because the velocity which means speed changes constantly.

-Purpose of the experiment

To find out the relationship among position, velocity and acceleration for linear, we will use Motion sensor, Xplorere GLX and the cart.

-What concept is being explored or investigated

The concept, that direction or magnitude of acceleration and velocity, depending on velocity and position, will be investigated through experiment.

-Hypothesis

The position graph of the cart will decrease first and increase again as it getting closer to the cart and sliding back. The velocity graph will be negative at first and then become positive. And the acceleration of the graph will be constant since the change of velocity is constant.

Materials

-Motion Sensor , GLX , plane and cart, the track for cart, and the book to make track inclined.

Experimental Design

We will set the track inclined, and we will put the censor on the top. After we set up GLX and other tools, we will push the cart forward the hill that we made by book. The car will slide down back. The censor will recognize the speed and position, and the graph will be shown automatically.

Independent variable:  As we push the cart to the top of the track, the displacement will be changed. Thus the position will decrease as the cart go near the censor, and it increase as the cart go back to his position. But we are not looking for the difference between the products which has two different displacement, it cannot be a independent.

Dependent: As the position of the cart is changed, the velocity and acceleration is changed too following its original function, position.

Control: Since we are human being, we cannot push the cart with same force every time. So it can be changeable. Also the angle of the road or how big the frictions are, is chageable too.

Procedure

1.       Connect the GLX and motion sensor

2.       Turn on the GLX

3.       Push the button Graph‘

4.       Make a inclined road for car by using books and track(pasco).

5.       Place the cart facing the sensor.

6.       Check the sensor if it reflect the cart.

7.       Press Start (play) button to record the graph of cart.

8.       Push the same button to end recording.

9.       Press check mark button2 times.

10.   Choose the ‘more’ button.

11.   Then you can chose velocity or acceleration.

12.   Press F3and chose Linear Fit.

13.   Press Check button 3 times

14.   Select the region.

15.   Press ceck to open tools.

16.Record average value acceleration in the lab report.

Data table

Data table

Item	Value
Acceleration (slope)	0.782±0.187 m/s^2
Acceleration (avg)	0.55 m/s^2

Graph

Position-Time Graph(m-s)

Velocity-time Graph(m/s-s)    

 Acceleration- Time Graph(m/s^2-s)

 Conclusion

 The position graph we got makes a concave up graph which is decreasing first and then increasing. As we see the slope of position graph, we can think abou the velosity. velosity starts from the negative point since the position graph was decreasing at first. But velocity becomes positive later as the poesition graph was increasing. The slope of the velocity-time graph  increases constantly. So the acceleration was constant. From this experiment we can see the relatioship betwwen position, velocity and acceleration. Because the slope of former graph is realated to next graph. My hypothesis is almost correct. velocity changed from negative to positive and the acceleration is constante. The error we got was unperfect graph. It is not clearly smooth because the sesor reflected other small things too, not only cart. And sometimes the cart hit the sensor so it influence to speed.   To improve this, we need to be more careful when we do experiment.  

 1. Describe the position versus time plot of the Graph screen. Why does the distance begin at a maximum and decrease as the cart moves up the inclined plane?

     The position in this experiment is the distance between sensor and the cart. The reason it begins at a maximum is, it was farder when the cart start to run. and it gets closer as it goes up(get closer to sensor)

.

 

   2. Describe the velocity versus time plot

     

As the time pass, the velocity increase. And we can know that the rate of increasing is constant becuase it is a straight line.

 

   3. Describe the acceleration versus time plot of the Graph display

   

  The acceleration is almost constant. it is straight line which does not go up or down.

 

   4. How does the acceleration determined in the plot of velocity compare to the average value of acceleration fromthe plot of acceleration. 

 

SInce the slope of velocity means acceleration, it is almost same value with average value of acceleration. Because average value of acceleration will be (Vf-Vi)/(Tf-Ti).  

Physics and Measurement Lab

1.       Organizing Data. Calculate the volume of the wooden block for each trial. V=L xW x T

	D	F	H	M	P	10
Length	4.3cm	5.5cm	7.0cm	7.5cm	7.6cm	10.1cm
Width	3.6cm	3.6cm	3.7cm	7.4cm	7.6cm	8.0cm
Tickness	3.5cm	3.6cm	3.7cm	4.3cm	3.8cm	3.7cm
Mass	27.6g	38.8g	51.2g	96.0g	161.1g	177.0g
Volume	54.2cm^3	71.3cm^3	95.8cm^3	238.6cm^3	219.5cm^3	299.0cm^3

2.       A. Difference between the smallest length measurement and largest length measurement.

Blobk (10) has the length of 10.1 cm and Block D has the length of 4.3 cm.

10.1cm  -  4.3cm=5.8 cm

B. Difference between the smallest calculated volume and largest volume.

The largest volume: 298.96 cm^3   The smallest volume: 54.18 cm^3

299.0 cm^3– 54.2 cm^3 = 244.8 cm^3

C. How does the multiplying several length measurements together to find the volume affect the precision of the result?

Because we choose the smaller significant number between two measurements when we multiply several measurements, it will make the significant number smaller,. Therefore the precision of the result will be decrease, which means it will be less accurate as you multiplying numbers.

3.       If you drop blocks from a same height, will it take same amount of time?

No, because it is not possible to make accurate data by human’s hand. But I think It should take same amount of time because all blocks have a same density since they all are made of up same substance. Only elements that can influence to the speed of time when the objects are falling from the same height are frictional force and density. But the frictional force between air and surface does not influence really in this experiment. Therefore it should take same amount of time to fall down.


4. Make a scatter plot of the distance versus time ot the block's fall.

Block	M	P	F	10	H	D
Time (s)	.78s	.585s	.725s	.60s	.56s	.47s
Distance	1m	1m	1m	1m	1m	1m

5.       Find the ratio between the mass and the volume. Based on your data, what is the relationship between mass and volume?

Density explains the relationship between mass and volume, because mass over volume equals density.  The ratio between the mass and volume is about 1:2, but I could not get the exact ratio because of the errors. If I graph the volume-mass graph, we will get the constant slope.

6.       Explain the error that could affect your results. Consider method error and instrument error.

Because the ‘seconds’ is a small unit to see the huge different, depending on how fast we click the stop button of time measurement made the result different. Example, we thought we click the button as soon as the block tough the floor, but it could be 0.20 seconds later. The result of time that we suppose to get should be all same but I got errors because of difficulty of perfect measuring. And when we measured the length of block, we might made mistake too. We could find out that there are the errors because our data does not follow the theory exactly.

7. Because each students will have different result even though it is a small error. But by exercising few times by different people, we can get more exact result. If each student has similar data, it means it is more precise. And if someone’s result makes more sense depending on theory, it means it is more accur