Group1.1-2-EB

=Pair A Sammy and Dylan= Pair A PAIR B: ELENA EMILY Compare: Qualitative Representations of Motion: Emily Van Malden Elena Solis Dylan Waldman Sammy Wolfin
 * Group Members:**


 * Period 2**
 * Date Completed:** 9/13/10
 * Date Due:** 9/14/10


 * Objective:**What are the different types of motion? What is the best way to represent the motion?


 * Procedure for Time Graphs:**

> *use the same person for all trials and have that person holding a flat object such as a binder
 * 1) Set up Data Studio to record position, velocity, and acceleration graphs.
 * 2) Plug in motion detector
 * 1) No motion- record self standing still
 * 2) Increasing speed toward-record walking toward detector, walking faster as you get closer.
 * 3) Increasing speed away- record walking away from detector holding binder walking faster as you get farther away.
 * 4) Constant speed toward-record walking towards detector moving at the same speed.
 * 5) Constant speed away- record walking away from detector moving at the same speed.
 * 6) Decreasing speed toward- record walking away from detector decreasing speed as you move toward it.
 * 7) Decreasing speed away- record walking away from detector decreasing speed as you move away from it.
 * 8) Take screen shots or draw graphs of the experiment for each run.

Procedure for Ticker Tape Diagrams:
 * 1) Set Up Spark Timer
 * 2) Pull piece of tape through spark timer at a constant speed
 * 3) Pull piece through spark timer, starting out slowly then increasing the speed
 * 4) Pull piece through spark timer, starting out quickly then decreasing the speed
 * 5) Darken marks with marker
 * 6) Take pictures to record data

DATA: Actual-

Some of these vt and at graphs are not very convincing... they look crazy! Theoretically *For the theoretical Motion diagram, see above. In this case it is the same as out actual.

good that you included the theoretical version! at least I know you get it.

**Analysis and Data Questions:** 1. How can you tell there is no motion on a... a. Motion diagram -On a motion diagram if v=0 and a=0, that means there is no velocity or acceleration. There is no motion. b. Ticker Tape Diagram - There will be no dots on the tape, because the tape will never move through the sparks which make the dots on the paper. c. Position vs. Time Graph - The position will remain constant as time goes on (a horizontal line) when there is no motion. d. Velocity vs. Time Graph - The velocity will remain constant at zero as time goes on (a horizontal line) when there is no motion. e. Acceleration vs. Time Graph - There will be no acceleration and it will remain constant as time goes on (a horizontal line) when there is no motion. 2. How can you tell your motion is steady on a... a. Motion diagram - If the velocity arrows are all facing the same direction, and are the same size the motion is steady. Acceleration must also equal zero (a=0) in order for a motion diagram to show steady motion. b. Ticker Tape Diagram - As the tape moves through the ticker at a constant speed, the dots the ticker produces on the tape will be evenly spaced along the whole tape. If they are evenly spaced, one can assume the motion was constant or steady. c. Position vs. Time Graph - If someone or something is moving at a constant speed towards a sensor, the line on the graph will start high and will produce a line with a negative, constant slope. As time goes by, the position of the thing or person is getting closer and closer to the sensor at a steady rate. There should be no curves in the graph. For a person or object that is moving further from the object, the line will have that same steady slope, but it will be positive. This is because as time passes, the position is getting further and further from the original place which was closer to the sensor. d. Velocity vs. Time Graph - If the line is horizontal, the velocity is constant. However, the way you can tell the difference between constant motion and no motion in a velocity vs. time graph is if the velocity is positive (above the x axis) or negative (below the x axis). The line will be horizontal, but shown to be positive or negative will prove the person or object is moving at a constant rate rather than at no rate. e. Acceleration vs. Time Graph - If something is moving at a constant rate, there is no acceleration and therefore the object or person will be moving at a constant speed. This means that on the graph, the line will be shown as a horizontal line on the x axis because there is no acceleration to be recorded. 3. How can you tell that motion is fast vs. slow on a... a. Motion Diagram - On this kind of diagram, a longer velocity arrow means that the object or person is moving faster. If the arrow is shorter, the object or person is moving slower. b. Ticker Tape Diagram - On the ticker tape diagram, if the tape is moving fast through the ticker machine the dots will be spread apart with a greater difference in between each set of dots. If the tape is moving slowly through the ticker machine, the dots will appear extremely close to each other. c. Position vs. Time Graph - If the position is changing at a fast rate, the graph will curve and dramatically drop or raise depending on if the object or person is moving towards or away from a sensor. If the position is changing at a slow rate, the graph will become closer and closer to a horizontal line because the distance will not be changing quickly with the passing of time. d. Velocity vs. Time graph -If the line on the graph is moving away from zero it is continually getting faster and faster but if it is moving towards zero it is getting slower and slower. e. Acceleration vs. Time graph - Acceleration graphs are hard to tell whether the object or person is moving fast or slow because it shows how quickly something accelerates, not the actual speed. 4. How can you tell you changed direction on a: - Motion Diagram: answer? - Ticker Tape Diagram: You cannot tell on this type of diagram because you can only insert the paper in one direction. - Position vs Time Graph: You can tell when direction is changed on this type of diagram when the slope is switched from negative to positive and positive to negative. When an object is moving away from the censor, the slope is positive and when an object is moving towards the censor, the slope is negative. - Velocity vs Time Graph: You can tell the change in direction on this graph by where the point are located relative to the x axis. When an object is moving towards the censor, the points are below the x axis and when an object is moving away from the censor, the points are above the x axis. Acceleration vs Time Graph: You can identify a change in direction on this graph by the height of the peaks. When moving towards the censor, the peaks get lower and lower, and when moving away from the censor, the peaks get higher and higher. 5. How can you tell your motion is increasing on a: - Motion Diagram: - Ticker Tape Diagram: As motion increases, the dots on the paper spread further and further apart - Position vs Time Graph: The slope gets steeper and steeper as motion increases - Velocity vs Time Graph: The graph will have a steeper curve as motion increases Acceleration vs Time Graph: This graph behaves similarly to the velocity vs time graph. As motion increases, the curves get steeper 6. How can you tell that your motion is decreasing on a…
 * 1) Motion diagram - if the arrows seem to be getting shorter in length, then your motion is decreasing
 * 2) Ticker tape diagram – if your dots get closer and closer together, that means that the tape is moving slower and slower, giving the SparkTimer a chance to get more dots on per cm.
 * 3) position vs. time graph – to notice motion decreasing, one would have to look at their curved graph and look for anywhere the slope goes from steep to shallow, regardless of sign (+/-). That means that the person is covering less and less distance per unit time, signaling that the person is slowing down.
 * 4) velocity vs. time graph – To tell if your motion is decreasing on a velocity graph, simply look to see if any line seems to be heading toward zero. Whether its a line coming from a big negative velocity up to a very tiny negative one, or a line coming down from a big positive velocity to a small positive one, the speed of the object (the absolute value of velocity) is decreasing.
 * 5) acceleration vs. time graph – It's very hard to tell from these graphs if an objects motion if increasing or decreasing for all it is is a measure of how fast the velocity of an object is changing. It doesn't tell you the actual speed of the object.

**Discussion Questions:** 1. a. Motion diagrams are very simple to read. The bigger the arrows, the faster an object is moving. The smaller the arrows, the slower its moving. If the arrows are the same size, then the speed is constant. Basically, length = speed. b. The Ticker time diagram is a very simple method to record an objects motion and speed. The farther apart the dots are the quicker the silver tape was moving. The closer the dots, the more slowly the tape was moving. If the dots all seem to be equidistant from each other, then the tape is moving at a constant rate. c. position vs. time graph helps a person visually record how far a person moves toward or away a specific location and how long it takes them to get to said spot. Overall though, by looking at the slope in certain areas, one can notice said person's speed at different times in their trips. d. velocity vs. time graphs can show a scientist, in its own way, just where a person went for if it's values are negative after 5 seconds, the person moved toward the sensor for 5 seconds. However, if the velocity is positive after 5 seconds, the person moved away from the sensor. e. acceleration vs. time graphs measures the rate that velocity changes which can tell us whether any change in velocity was positive or negative, whether velocity was slowly increasing toward positive values or toward negative values.

2. The disadvantage of using both motion diagrams and the ticker tape diagram is that you can not get numerical data for the speed of the object. With the ticker tape diagrams the only way to gauge the speed is by looking at the distance between the dots on the tape. This can tell you if the object sped up or slowed down based on the dots but now a number of how fast the object was moving. The motion diagrams can tell you when something sped up or slowed down and which way the acceleration is going but cannot give you specific data. The disadvantage of using the velocity vs time and acceleration vs time is that human error is shown in the data. The movement of clothes or another object will be reflected in these graphs and even though we were holding a binder there still could have been excess movement. The position vs time graph does not really have a disadvantage unless the sensor is not pointed directly at the object in question.

3. a. No motion is when the object or person is standing still and not moving in any direction. Therefore the velocity and acceleration are zero. b. Constant speed is when a person or object is moving but its velocity and acceleration remain the same even though the distance will change. The person is moving at the same rate so the velocity is constant. The acceleration is 0 because the object is moving at a constant rate. c. Increasing speed is when a person or object starts off at one speed and gradually starts to move faster. The distance will change because its in motion. The velocity will increase as the speed increases. The acceleration will also increase because acceleration is the change of velocity over time. d. Decreasing speed is when a person or object starts off at one speed but gradually starts to slow down. The distance will change because it is moving. The velocity will also change, it will decrease as the person or object slows down. The acceleration will go in the opposite direction if the velocity so when the velocity is decreasing the acceleration is increasing.


 * Conclusion:**

In general, from this motion lab, we were able to conclude that acceleration, velocity, and position are all related. First, we saw that there was a relationship between position and velocity. If an object’s displacement starts to decline or become more negative, then the velocity is negative. If the object’s displacement starts to increase and become more positive, then the velocity is positive. We also saw that when someone’s speed (the total distance an object covers over time) increased, their velocity (the displacement or distance from the starting point over time) increased. We also noted the relationship between velocity and acceleration: if the rate-of-change (slope) of velocity is positive, then acceleration is positive. If the slope of velocity is negative, then acceleration is negative. To get to this conclusion, we studied 5 different types of motion graphs: Motion Diagrams, Ticker Tape Diagrams, Distance vs. Time Graphs, Velocity vs. Time graphs, and Acceleration vs. Time Graphs. The Motion Diagram was useful when we wanted to quickly glimpse at a graph, and understand all the concepts surrounding it. It’s easy to read and interpret and leaves very little doubt as to what the velocity or acceleration is. However, it can’t give an exact numerical value as to what the new position may be. This is where the Distance vs. Time graph can be handy, for anyone willing to spend a little extra time. By careful examination, the Distance vs. Time graph (with its specific rate-of-change values and concavity) can show what both the velocity vs. time graph and the acceleration vs. time graph should look like. However, there were quite a few chances for human error during this experiment. First off, it was hard to tell exactly where the motion sensor was pointing. The sensor could have easily picked up the rustling of our clothes or the scissor-like movement of our legs which would have thrown off velocity and acceleration. Also, we were probably not able to regulate our speed perfectly; we might not have increased or decreased at a steady rate, and we probably were not able to keep our constant speed perfectly consistent. This too would have affected the velocity and acceleration. good causes of error

=A CRASH COURSE IN VELOCITY 9/20/10= Samantha Wolfin, Emily Van Malden, Dylan Waldman, Elena Solis
 * Group Members:**


 * Hypothesis:** The purpose of our experiment, was to analyze velocity in different circumstances, and see how position and time are are used to calculate it. We hypothesized that the Ticker Tape for each car would reveal dots separated by a constant distance, with the faster car's dot farther apart then the slower car's. We also predicted that the position vs. time graph of each car would be a strait line, with a positive slope, with the faster car's slope more steep, then the slower car's.

**Experiment One:** For this experiment, we set up the cars exactly 600 cm or 6 m apart, one at each end of the measuring tape. CMV (constant moving vehicle 1) was our fast car, which from our ticker tape experiment, had an almost constant velocity of .3006 meters per second. CMV 2 was our slow car which had an constant velocity of .1145 m per second. We started the cars at the same exact time. By careful observation, we noticed that the cars crashed about 1.5 meters from where the slower car started. That meant that the fast car traveled about 4.5 m. However, to solidify our observations, we did some calculations to find the exact place the cars met:

Fast Car: .3006 m/s Slow Car: .1145 m/s

.3006 m/s + .1145 m/s = .4151 m/s __.3006 m/s__ = .7242 travel 4.35 meters .4151 m/s

.7252 x 6.00 m = 4.35 m that the fast car traveled

6.00 m – 4.35 m = 1.65 m that the slow car traveled There is no physics shown. What equations did you use? What relationships are there?

It took the slow car about 14 .45 seconds to travel 1.65 m and crash into the fast car. It took the fast car about 14.47 seconds to travel and crash into the slow car.

**Experiment Two:** For this experiment, we set up the fast car at the start of the measuring tape. We then placed the slower car exactly one meter in front of the faster car. We started the cars at the same time. From our observations, it seemed that the faster car caught up with the slower car 1.53 from the faster car's starting place (.53 m from the slower car's starting place). However, to solidify our observations, we did some calculations to find the exact place the cars met:

CMV 2: y = .3006 (m/s) x CMV 1: y = .1145 (m/s) x + 1.00 .3006 (m/s) x = .1145 (m/s) x + 1.00 .1861 x = 1.00 x = 5.37 seconds (time it took the fast car to pass the slow car) You use x as a variable above, but as multiplication below. Do not use x as a variable, keep the symbol for the actual value, in this case, t.

CMV 2: y = .3006 (m/s) x 5.37 sec y = 1.62 meters that the fast car traveled CMV 1: y = .1145 (m/s) x 5.37 sec y = .615 meters that the slow car traveled

The order of presentation is not very deliberate. Please look at the format requested.
 * Data:** each of the trails took a while for us to run a decent test, but we managed to record 4 of each of our runs:
 * Ticker-Tape Experiments**

Slow Car Traveled || Distance (m) Fast Car Traveled || Time (sec) it took for Crash to Occur || The longer distance is the faster car.
 * Experiment One**
 * || Distance (m)
 * Run 1 || 1.65 || 4.35 || 14.46 ||
 * Run 2 || 1.62 || 4.38 || 14.27 ||
 * Run 3 || 1.67 || 4.33 || 14.51 ||
 * Run 4 || 1.61 || 4.39 || 14.2 ||
 * Experiment Two**
 * || Distance (m) Fast Car Traveled || Distance (m) Slow Car Traveled || Time (sec) it took for Fast Car to Slow Car ||
 * Run 1 || 1.62 || .615 || 5.37 ||
 * Run 2 || 1.61 || .607 || 5.18 ||
 * Run 3 || 1.65 || .645 || 5.44 ||
 * Run 4 || 1.64 || .640 || 5.42 ||

You did not analyze these results or answer any of the follow up questions.