Group4.1-2-EB

Juven Thorsi (AKA Steve Thorwarth and Justin Tosi)

Anthony And Sam

**Group:** Sam F., Steve T., Anthony I., Justin T. Period: 2 Due Date: 9/21

**"A Crash Course" Lab** **Hypothesis:** To predict and determine the collision and catching up points of Constant Motion Vehicles using algebra, graphs, and values received from experiments. We predict that the ticker tape dots will be equally separated because the CMVs are traveling at a constant velocity. The faster car will have a steeper slope because it is traveling at a higher velocity, therefore it will be father away from the spark timer faster. **Materials:** 1 two-battery CMV (fast) 1 one-battery CMV (slow) Ticker Tape Spark Timer Meter Stick Tape Measure Masking Tape

Procedure: **__Finding the Average Speed of the CMV:__** 1. Slide ticker tape through spark timer and tape it to the end of the CMV, on the backside.

2. Set spark timer to 10Hz

3. Turn spark timer on and then turn on the CMV

4. When more than 30 dots are recorded stop both the spark timer and CMV

5. Measure the distance of each dot from the beginning of the ticker tape using a meter stick

6. Record Data

**__CMV Colliding:__** 1. Tape down a tape measure for 6 meters across the floor.

2. Place both CMVs at the opposite ends of the tape measure, making sure that they are 600 centimeters (6 meters) apart

3. Turn them both on and let them collide

4. Stop both CMVs and record the length at which they collide

**__CMV Catching Up:__** 1. Tape down a tape measure for 6 meters across the floor.

2. Place the faster CMVs at the beginning of the tape measure (0 meters) and the slower CMV at 1 meter or 100 centimeters.

3. Turn them both on and let the faster CMV catch up to the slower one

4. Stop both CMVs and record the length at which the faster one catches up to the slower one

**Data:**

**Ticker Tape Data for Fast and Slow Car at Constant Speed** Why are these %errors here? What is it percent error of? Why are there two and why are they nearly identical? HELP!

**Ticker Tape Graph for Fast and Slow Car at Constant Speed**

This graph and chart can be found here: please also include a screen shot.

Data: From the graph, we can see that the slow car traveled at an average speed of 10.878cm/s and the fast car traveled at an average speed of 32.925cm/s.

Calculations:







what are these?

**Find another group with a different CMV speed. Find the position where both CMV’s will meet if they start //at least//** **600 cm apart, move towards each other, and start simultaneously.**



The cars will meet 2.49m from the Slow Car’s starting point on the right. where are calcs for this?

**Find the position where the faster CMV will catch up with the slower CMV if they start //at least//** **1 m apart, move in the same direction, and start simultaneously.**

aren't these calcs for a different lab?

It will be 1.5 m from the start of CMV2 where CMV2 will catch CMV1.

__Discussion Questions__:

1. The position-time graph is equivalent to the velocity graph because the ticker tape dots that were measured and recorded for the graphs were taken when the car was pulling the tape at a constant velocity. Throughout the time recorded the tape was being pulled at a constant speed, causing no change to the velocity of the graph over time, and no acceleration to affect the position over time graph.

2. It was okay to set the y-intercept equal to zero because the recording began where the first dots on the spark tape were found that had an almost identical space measured between it and the dots after it. Because the measurements began where those first dots were with no space before it, there was no distance before the first dots and time recording.

3. The R^2 value is a percentage that tells how close to precise recorded points are on a graph to the expected results line. The percentage is the amount of points on the graph that are on that projected results line. The higher percentage means that there are more dots on the graph that are on the line that is the projected results and means the data is more precise.

4. If the cars going at one another were traveling at the same speed they would meet at the exact centre of the distance between them. In the case of our experiment it would be at 3m. If one car was chasing another at the exact same speed it would never be able to catch the other car.

5. The slow car and the fast car are at the same distance when the red line meets the yellow line in this graph. This point is at 150 cm and takes approximately 4.55 seconds.



The two cars are at the same point when the total distance traveled by the two cars is equal to 600 cm. This is at approximately 13.7 seconds, and is where the red and blue lines cross. Because the slow car started at 6m it begins at 6m and comes closer until it collides with the fast car.

6.



You cannot tell when the cars collide in this graph because we do not know how far they have traveled or when they reach 600 cm in total distance, all we know is how fast the cars travel.

**Conclusion:**

For the most part, our results were expected. One would expect that the fast car would cover more distance than the slow car in any number of seconds. Therefore, it was only logical that the fast car was farther away from its starting point than the slow car in the Collision Trial. For the Chase Problem, we figured out the number of centimeters that the fast car would gain on the small car every second. We then did the initial distance between the two cars divided by the number of centimeters gained per second to find the seconds. Finally, we utilized our knowledge of the velocity equation to find out how long it took before the fast car caught the slow car. This is procedure or so general that there is little info. You don't discuss any quantitative or actual results.

Just like in our previous lab, human error may or not have had a large effect on our results. Our mistakes could have been as simple as not measuring accurate enough or not carefully looking where the two cars either crashed into each other or caught up to each other. Our error was a little high, 14%, and we may need to have a chat with Mrs. Burns about why our error was so high. you are very offhand about these errors... definitely need to elaborate.



**Group:** Sam F., Steve T., Anthony I., Justin T. Period: 2 Due Date: 9/15 **Motion Lab**  **Purpose:** Our goal is to determine the different types of motions and to find the best way to represent the motion. = =  **Procedure for Motion Detector Lab**

1. We set up our motion detector and our computer on top of one of the school garbage cans so that the motion detector would be pointed at my waist area.

2. One member of our group completed the different types of movement listed in the lab: No Motion, Increasing Speed Toward, Increasing Speed Away, Constant Speed Toward, Constant Speed Away, Decreasing Speed Toward, and Decreasing Speed Away. We made sure to hold a flat notebook to make sure that our measurements were accurate.

3. After collecting our data with the motion detector, the USB link to our computer provided Data Studio the information it needed to produce different graphs, such as The Position vs. Time Graph, Velocity vs. Time Graph, and Acceleration vs. Time Graph.

4. We analyzed our data and drew the “ideal” lines for our graphs that we would have recorded if we preformed our experiment under ideal conditions.

**Video for Step 2 of Procedure** media type="file" key="No Motion.mp4" width="300" height="300"media type="file" key="Increasing Speed Toward.mp4" width="300" height="300"media type="file" key="Increasing Speed Away.mp4" width="300" height="300" media type="file" key="Constant Speed Toward.mp4" width="300" height="300"media type="file" key="Constant Speed Away.mp4" width="300" height="300"media type="file" key="Decreasing Speed Towards.mp4" width="300" height="300"

media type="file" key="Decreasing Speed Away.mp4" align="left" width="300" height="300"

I like this! This is great to include.

**Procedure for Ticker Tape Lab** 1. We cut three 12-inch pieces of Ticker Tape for our three different Trials: Constant Speed, Increasing Speed, and Decreasing Speed.

2. After plugging in the spark timer, our group needed to decide if all of our runs should be done at the 10Hz or 60 Hz speed. After trying one unsuccessful trial at 10Hz speed, we decided to use the 60 Hz speed for all of the trials.

3. One person in our group ran the ticker tape through the Spark Timer in the different ways mention in Step 1.

4. After we finished our three trials, we came up with conclusions about the relationship between speed and the distance between the dots on the ticker tape.

__Data:__

Great to show ideal lines right on top of the experimental graph.

**Analysis and Data Interpretation**

1. How can you tell that there is no motion on a…
 * 1) Motion diagram
 * 2) Ticker tape diagram – If there is one mark on the tape, you know that the tape has not moved and the machine keeps drawing a mark on the same exact spot.
 * 3) position vs. time graph – If the position has stayed consistent and not changed, then you know the position has not moved and there has been no motion.
 * 4) velocity vs. time graph – If there is a horizontal line at 0, then you know there is no motion because there is no velocity and the velocity stays at 0.
 * 5) acceleration vs. time graph - If there is a horizontal line at 0, then you know there is no motion because there is never any acceleration and it stays at 0.

2. How can you tell that your motion is steady on a…
 * 1) Motion diagram ???
 * 2) Ticker tape diagram – If there are many marks on the tape that all have about the same distance in between them, you know you are at constant motion.
 * 3) position vs. time graph – If there is a straight diagonal line on this graph you can tell that the motion is steady because the position is changing at a constant rate (slope of the line). The line is straight because the rate at which your position changes is the same each time. Your position would start high if you started far away form the sensor, but would lower as you travel closer to the sensor. This is the same case for the opposite situation too.
 * 4) velocity vs. time graph – If there is a horizontal line on this graph (that is not at y=0) you can tell you have steady motion because the velocity stayed constant through the entire test.
 * 5) acceleration vs. time graph - If there is a horizontal line on this graph (that is not at y=0) you can tell you have steady motion because the acceleration never changes through the test. You never go faster or slower.

3. How can you tell that your motion is fast vs. slow on a…
 * 1) Motion diagram ???
 * 2) Ticker tape diagram – You know your motion is fast when there is a lot of space between your marks on the tape. This is because the tape is pulled out faster, thus giving the machine less time to make marks on the tap. You know its slow when there is not a lot of space between your marks because the machine gets more time to make more marks on the tape when it is pulled out slower.
 * 3) position vs. time graph – You know you have fast motion when there is a large drop or rise (depending on whether you are moving towards or away from your sensor) in your graph because your distance is being changed a rapid rate.
 * 4) velocity vs. time graph - Fast motion is recognized on this graph by a steep line. As the line becomes more horizontal, the motion becomes slower.
 * 5) acceleration vs. time graph - You can not tell if your motion is fast or slow on this type of graph.

4. How can you tell that you changed direction on a... a. Motion Diagram- The arrows of velocity shows what direction you are going in. Left is for towards, right is for away. b. Ticker Tape Diagram- You are not able to tell when you have changed direction on a ticker tape diagram. This is because when you are sliding a piece of piece through this device, sliding it both ways make the dots look the same. c. Position vs. Time Graph- The lines that the two opposite graphs (towards/away) make are reflections of each other, therefore if you take two trials and they are reflections of each other then you know that you have changed direction. d. Velocity vs. Time Graph- Like the position vs. time graphs, the lines that the two opposite graphs make are reflections of each other. If you take two trails and they are reflections then you know that you have changed direction. e. Acceleration vs. Time Graph- You are not able to tell that you changed direction, because acceleration does not keep track of direction, it only keeps track of displacement over an amount of time.

5. How can you tell that your motion is increasing on a... a. Motion Diagram- If motion is increasing, the acceleration arrow will match the above arrows of velocity and the arrows will become larger for each arrow. b. Ticker Tape Diagram- If your motion is increasing on a ticker tape diagram, you will be able to notice because there will be more frequent ticks. The ticks will be closer together. c. Position vs. Time Graph- If your motion is increasing on a position vs. time graph, you will be able to notice because the graph grows exponentially at the end, this is due to the fact that your motion is increasing. d. Velocity vs. Time Graph- If your motion is increasing on a velocity vs. time graph, you will be able to notice because the data will start at 0 on the Y-axis and slant away from it. e. Acceleration vs. Time Graph- If acceleration is increasing on this type of graph then the slope of the line will be positive.

6. How can you tell that your motion is decreasing on a... a. Motion Diagram- If motion is decreasing, the acceleration arrow will be the opposite of the above arrows of velocity and the arrows will become larger for each arrow. b. Ticker Tape Diagram- If your motion is decreasing on a ticker tape diagram, you will be able to notice because there will be less frequent ticks. The ticks will be farther apart. c. Position vs. Time Graph- If your motion is decreasing on a position vs. time graph, you will be able to notice because the graph flattens out at the end, this is due to the fact that your motion is decreasing and it will flatten out until you stop. d. Velocity vs. Time Graph- If your motion is decreasing on a velocity vs. time graph, you will be able to notice because the data will start above the Y-axis and end at 0 on the Y-axis. e. Acceleration vs. Time Graph- If acceleration is decreasing on this type of graph then the slope of the line will be negative.

__Discussion Questions:__

>>
 * 1) What are the advantages of representing motion using a…
 * 2) Motion diagram - With a motion diagram it can be seen which direction an object is moving in and how far they travel in that direction.
 * 3) Ticker tape diagram – The dots on the ticker tape make it very easy for it to be seen that as the tape is pulled faster through the ticker, the dots are farther apart. This is a good way to compare speeds of how fast the tape was being pulled through the ticker.
 * 4) position vs. time graph – This graph shows where an object is at certain durations of time in relation to the sensor. This graph shows which direction an object is moving (either towards or away) and this can determine the velocity of the object.
 * 1) velocity vs. time graph – This graph shows the velocity of an object at certain durations of time. This graph shows the velocity of the object going towards or away from the sensor.
 * 2) acceleration vs. time graph – This graph show the acceleration and deceleration of an object over certain durations of time. This graph can be used to see the acceleration or deceleration of the object.

Watch formatting issues... numbering
 * 1) What are the disadvantages of representing motion using a…
 * 2) Motion diagram - In a motion diagram you cannot tell what velocity or the acceleration that an object travels in.
 * 3) Ticker tape diagram- The ticker tape diagram does not determine the actual velocity of acceleration of the tape being pulled through the ticker, it only shows comparative changes in velocity and acceleration.
 * 4) position vs. time graph – This graph shows the position of an object after a certain duration of time. This can can be used to estimate velocity and acceleration of an object, but is not completely accurate.
 * 5) velocity vs. time graph – This graph shows the velocity of an object at certain durations of time. This graph does not show the position or location of an object, and does not show the direction that the object is traveling to.
 * 6) acceleration vs. time graph – This graph shows the acceleration of an object, but does not show the direction or speed of the object.
 * 1) Define the following:
 * 2) No motion – An object has no motion when both its velocity and acceleration are equal to zero.
 * 3) Constant speed – The speed of an object that has no acceleration and is moving at the same speed.
 * 4) Increasing speed – The speed of an object as a result of an increase in acceleration for that object.
 * 5) Decreasing speed – The speed of an object as a result of a decrease in acceleration for that object.

**Conclusion**

For the most part, our results were expected. When analyzing the Data portion of our lab, one can see the graphs that we actually recorded with the motion detector and also the blue lines that Anthony drew in to show the ideal graph and data under ideal conditions. For the most part, our trials were accurate to what they would have been under real conditions and only the irregularities of our movements were picked up on the motion detector.

Like Mrs. Burns explained, humans tend to take a short pause after each step, causing a short lull in motion after taking each step. In order to try and eliminate this problem, we placed a flat book in front of where the motion detector was pointed on our respective bodies and tried to “glide” instead of walk. This helped reduce some of the error, but as one can tell from our graphs in the Data section of this lab, we were not completely successful. This error could have been due to what was just explained or because we could not completely follow the instructions given to us. For example, it is almost impossible to keep a perfectly constant speed when walking toward or away from the motion sensor. As a result, we can conclude that human error was the main cause for the inaccuracies in our lab. How could you address this sources of error?

We were able to establish the graphs of motion and solidify our prior knowledge on the subject. We also utilized different graphs and measures to record the different movements that were preformed in the lab.