Position: where an object is located in reference to its surroundings Distance: how far an object has traveled, regardless of direction Displacement: how far an object is from its starting location; must have a reference point and include a direction Velocity: rate of change of position (how fast an object is going). This can be negative. Speed is the same thing, but can't be negative. Velocity must reference direction. (Measures displacement, not distance) Vectors: size and direction Scalar: size only

Lesson 1: Describing Motion With Words B,C,D

What (specifically) did you read that you already understood well from our class discussion? Describe at least 2 items fully.

Since these readings are about topics that have been covered in class, I was familiar with most of them. Two topics that I was already familiar with (from class) were the definitions of distance and displacement. Displacement refers to an object's overall change in position, and distance refers to how much an object has traveled overall. The example used with the physics teacher only reaffirmed my knowledge.

What (specifically) did you read that you were a little confused/unclear/shaky about from class, but the reading helped to clarify? Describe the misconception you were having as well as your new understanding.

A concept I had trouble with during class was the definition of scalar vs. the definition of vector. I did not understand if a quantity could be both a scalar and a vector, instead of just one or the other. For example, are all scalars also vectors, but not all vectors are scalars? (This is sort of like the statement "All squares are rectangles, but not all rectangles are squares") The reading helped me see that it is not possible for a quantity to be both a scalar and a vector. It can only be one.

What (specifically) did you read that you still don’t understand? Please word these in the form of a question.

I do not have any questions, as the questions I had from class were answered in the readings.

What (specifically) did you read that was not gone over during class today?

Instantaneous speed was not covered in class today. It is "the speed in any given instant in time". It is compared to the speed on the speedometer of a car. It is different from average speed because objects do not travel at consistent speeds all the time.

E

What (specifically) did you read that you already understood well from our class discussion? Describe at least 2 items fully.

I already knew from our discussion in class that the formula for acceleration is (final velocity - initial velocity) / time. This is a different formula from velocity. In class, we also talked about constant acceleration. This is when an object moves faster or slower at a consistent pace. This is unlike constant speed because the object is either getting faster or slower. The object stays in motion, but does not move at the same rate for a set distance. Instead, the velocity either increases or decreases by a constant amount each second.

What (specifically) did you read that you were a little confused/unclear/shaky about from class, but the reading helped to clarify? Describe the misconception you were having as well as your new understanding.

I did not have any questions from class that the reading helped to clarify.

What (specifically) did you read that you still don’t understand? Please word these in the form of a question.

I do not have any questions, as the questions.

What (specifically) did you read that was not gone over during class today?

We didn't go over the free-falling object in class. A free falling object is the acceleration of an object when it is dropped from above ground. A free falling object does not have constant acceleration. Instead, it goes faster and faster, so its acceleration increases as it falls.

Speed of a Constant Motion Vehicle Lab: September 9Partner: Nicole Tomasofsky

Purpose:The purpose of this lab is to find the speed of a CMV, a constant motion vehicle, and see what information can be gleaned from position time graphs. Also, from this lab, I am trying to find how precisely you can measure distances with a meter stick.

Objectives:

How precisely can you measure distances with a meter stick?

How fast does the CMV move?

What information can you get from a position time graph?

Materials:

spark timer

spark tape

meter stick

masking tape

CMV

Hypothesis:

How precisely can you measure distances with a meter stick? You can measure distances to the nearest millimeter using the meter stick. This is my hypothesis because I have used meter sticks in the past and know that there are millimeter marks on the meter stick, and they are the smallest unit of measurement.

How fast does the CMV move? 75 cm/s. This is my hypothesis because

What information you get from a position time graph? You can get the instantaneous speed and average velocity of an object.

Data:

Length of laptop = 30.0 cm

= 45.12 cm/s

The CMV moves 45.12 cm/s

Discussion questions

Why is the slope of the position-time graph equivalent to average velocity?

Slope is nothing more than rise over run, or y/x. The formula for average velocity is displacement over time elapsed. In my graph, position is the y axis, and time is the x axis. So in this case, y/x = displacement/time. This makes the slope equal the average velocity of the CMV.

Why is it average velocity and not instantaneous velocity? What assumptions are we making?

Average velocity is more accurate than instantaneous velocity because instead of just looking at one point on the graph, all our data is taken into consideration. The slope determines the average velocity, and individual plots represent the instantaneous velocity. Since we are using the slope of the line to find velocity, and not individual plots on the graph, we are finding the average velocity. We are making the assumption that the CMV is going at a constant speed.

Why was it okay to set the y-intercept equal to zero?What is the meaning of the R2 value?

It is okay to set the y intercept equal to zero in this situation because the y axis measures position, and as our CMVs do not travel backwards, it is impossible for them to have a negative position. The CMVs start at a position of (0,0) because the time and position are both zero.

What is the meaning of the R2 value?

The R2 value tells you how accurate your graph is. It does this by setting a trendline through all the points in the graph. Then, the R2 value tells you how close the trendline is to the points you plotted in your scatter gram. The closer to 1.0 it is, the more accurate your results.

If you were to add the graph of another CMV that moved more slowly on the same axes as your current graph, how would you expect it to lie relative to yours?

I would expect the graph to have a smaller slope. This means that my original graph would have a steeper slope than the 2nd, new, graph.

Conclusion:

For this lab, there were three objectives: How precisely can you measure distances with a meter stick? How fast does a CMV move? What information can you get from a position time graph? My hypothesis for the first question was that you could measure up to the nearest millimeter. It turns out that you can guess the distance between two millimeter marks, so you can get an even more precise measurement than I had predicted. I had also hypothesized that a CMV could travel 75 cm/s. But, my data shows that the speed of the CMV was actually 44.12 cm/s. Therefore, my hypothesis was wrong. I had also hypothesized that you could get two pieces of information from a position time graph: instantaneous velocity and average velocity. The data my partner and I collected supports this hypothesis.

There are many sources of error that could have contributed to inaccuracies. For example, the meter stick could have moved while my partner and I measured the distance between the dots. This problem could have been remedied by taping down the meter stick. Also, it was hard to get an accurate reading of the distances because the meter stick is made of wood, and the centimeter and millimeter marks do not sit directly on the page, next to the dots that my partner and I were measuring. Instead, they sit a couple of centimeters up, so depending on what angle you choose to read the measurement at, you could have different distances. Using a tape measure could have eliminated this source of error. It is important to learn how to take the proper measurements of a distance because in real life, a couple of centimeters could make a huge difference. For example, if an architect designs a building, but accidentally makes the door frames a couple of cm too small, then the doors can't fit. This would be a huge problem.

Overall, I feel that this lab was a success, and my partner and I made the best of the materials that were available to get the most accurate data.

Class Notes: Graph Shapes (At Rest and Constant Speed)

Lesson 2: Describing Motion With Diagrams

A,B,C

What (specifically) did you read that you already understood well from our class discussion? Describe at least 2 items fully.

There were two things that I read about that I already understood from our class discussion. They are:

Ticker tape diagrams

Ticker tape diagrams are used to describe motion. A long tape is threaded in a specialized machine, and dots are created on the tape. A dot is created X times a second, so the further apart the dots, the faster the tape is going. The closer the dots, the slower it is going. If the dots get more crowded on the paper towards the end, it is showing acceleration. However, this device only measures scalar quantities, as direction of movement is not recorded.

Vector Diagrams

Vector diagrams are diagrams with arrows and labels. There are two kinds of arrows. Ones that are labeled with "a" show acceleration (whether is is positive or negative) and arrows that are marked with "v" show velocity. If the object moving has positive velocity, the arrows get larger. Negative velocity means the arrows get smaller. If an object is traveling at a steady rate, the arrows are the same size.

What (specifically) did you read that you were a little confused/unclear/shaky about from class, but the reading helped to clarify? Describe the misconception you were having as well as your new understanding.

I did not have any questions from class that the reading helped to clarify.

What (specifically) did you read that you still don’t understand? Please word these in the form of a question.

I do not have any questions.

What (specifically) did you read that was not gone over during class today?

We went over everything in the reading in class.

Class Notes: Speed, Diagrams, Ticker Tape Diagrams

Motion diagrams show direction of velocity and aceleration

Constant speed:

Increasing Speed:

Decreasing Speed:

The Big Five Physics Equations (For Motion)

Lesson 3: Describing Motion with Position vs. Time Graphs

What (specifically) did you read that you already understood well from our class discussion? Describe at least 2 items fully.

I already knew from our classroom discussion that if two position time graphs of constant velocity were to be compared, the one that depicts the faster velocity would have the larger slope and the steeper graph.

Before reading this, I also knew that slope is equal to rise over run.This is a concept that I have explored both in math and in physics.The formula for slope, m= (Y1-Y2 / X1-X2) is something that I was familiar with before I read this lesson.

What (specifically) did you read that you were a little confused/unclear/shaky about from class, but the reading helped to clarify? Describe the misconception you were having as well as your new understanding.

A concept I had trouble with during class was whether position time graphs had a negative y axis.I was confused because velocity-time graphs could have negative y-values.This reading helped me see that it is impossible for an object to have a negative position.

What (specifically) did you read that you still don’t understand? Please word these in the form of a question.

I do not have any questions, as the questions I had from class were answered in the readings.

What (specifically) did you read that was not gone over during class today?

I believe everything in the reading was covered in class.

Lesson 4: Describing Motion with Velocity vs. Time Graphs

What (specifically) did you read that you already understood well from our class discussion? Describe at least 2 items fully.

I already knew from our classroom discussion that if the velocity-time graph was a straight horizontal line with a slope of 0, then the object that was represented would be either moving at a constant speed or at rest.

From class, I learned that the area of the region between the line of and the axes in a velocity time graph show the displacement.The information in the reading only reaffirmed my knowledge.

What (specifically) did you read that you were a little confused/unclear/shaky about from class, but the reading helped to clarify? Describe the misconception you were having as well as your new understanding.

I did not have any questions that the reading helped to clarify.

What (specifically) did you read that you still don’t understand? Please word these in the form of a question.

One question I have is: What if there is a negative velocity?Would displacement still be shown by the area of the region bounded by the line and axes?

What (specifically) did you read that was not gone over during class today?

I believe everything in the reading was covered in class.

Class Notes: Increasing and decreasing Speed Graphs

Activity: Graphical Representation of Equilibrium

Cart and Ramp Class Activity

Position time graph practice 9/15

Describe the motion of the car (qualitatively) during each segment.

AB at rest

BC constant towards

CD at rest

DE constant away

EF at rest

FG constant towards

GH constant away

Describe the change in position of the car during each segment.

AB none

BC 10 to 0 (-10)

CD none

DE 0 to -16 (-16)

EF none

FG -16 to 0 (16)

GH 0 to 14 (14)

Calculate the velocity of the car during each segment.

Distance / time

AB

BC -10/2 = -5 m/s

CD

DE -16/ .5 =-32 m/s

EF

FG 16/1 = 16 m/s

GH 14/2 = 7 m/s

What is its average speed for the entire 12-s?

Total distance/ Total time (add displacements without signs)

56 m/11 s = 5.1 m/s

What is its average velocity for the entire 12-s?

Displacement/ time

Final position – initial position = displacement

4/11 = .44 m/s

What is the acceleration of the car during each segment?

0 for each segment because they are constant speeds

Acceleration Graphs Lab: September 16

Partner: Nicole Tomasofsky

Objectives: What does a position time graph for increasing speed look like?What information can be found from the graph?Hypothesis:

What does a position-time graph for increasing speeds look like? It is a curved line, with a positive slope. The slope is getting steeper.

What information can be found from the graph? You can find the average speed and instantaneous speed.

Set up the ramp by placing the end of the track on a textbook.

Set up the spark timer by plugging it in and placing it at the top of the track.

Run a piece of spark tape through the spark timer and tape it to the cart.

Set the spark timer to 10 Hz

Set the cart at the top of the track and let it roll down the ramp.

Save this piece of spark tape.

Now, set the cart at the bottom with the timer.

Push the cart up, so the tape runs through the timer.

Save the tape and make sure there are at least 10 spark marks on each piece of tape.

Using a meter stick, measure the distance between the dots on both pieces of tape.

Record this data in an excel spreadsheet and analyze.

Halfway point = 0.60 s

2 points on line: (0,6) (0.5, 28)

slope = 44

instantaneous speed = 44 cm/s

End = 1.20 s

2 points on line: (0,31) (.3,36)

slope = 50/3

instantaneous speed = 50/3 cm/s

c) Find the average speed for the entire trip. Decreasing speed: distance traveled/ time elapsed = average speed = 66.40cm/2.0s =33.20 cm/s Increasing speed: distance traveled/ time elapsed = average speed =49.98 cm/1.20 s =41.65 cm/s

Discussion Questions:

What would your graph look like if the incline had been steeper?

The graph would have a larger slope and a steeper graph. The curve of the graph would be more predominant, since the acceleration would be greater.

What would your graph look like if the cart had been decreasing up the incline?

The initial curve would be steep and noticeable (since the cart is traveling faster in the beginning), but the line would flatten out. Also, the line would go away from the origin.

Compare the instantaneous speed at the halfway point with the average speed of the entire trip.

Increasing speed graph:

half way point has a velocity of 25 cm/s.

average velocity is 33.20 cm/s.

Average velocity is faster

Decreasing speed graph:

half way point has a velocity of 44 cm/s.

average velocity is 41.65 cm/s.

Halfway point velocity is faster.

Explain why the instantaneous speed is the slope of the tangent line. In other words, why does this make sense?Draw a v-t graph of the motion of the cart. Be as quantitative as possible.

You cannot find the slope (or change) one point--you need two points. A tangent line offers a slope, and since it touches only the point on the graph it is tangent to, it is representing the slope of the line. The slope of the one line shows the speed at that specific moment, which is instantaneous speed.

For my hypothesis, I stated that you could find the instantaneous speed and average speed from a position time graph. From this lab, I learned that you can also find determine initial velocity, and average acceleration. I also hypothesized that the position time graph for increasing speed would look like a curved line with a slope that is getting steeper. The graph is also moving away from the origin. This hypothesis proved to be correct.
Tehere are multiple possible sources of error for this experiment. For example, since we had two strips of tape, maybe we got them mixed up. This could have been easily remedied by labeling the strips of tape. Also, another error that could have occurred was that our measures of the distance between the dots were inaccurate. Maybe the tape moved around while we were measuring. This could have been fixed by taping the stick to the meter stick.

Lab: A Crash Course in Velocity

Stephanie Wang
Partner: Nicole Tomasofsky Purpose: The purpose of this lab is to determine the distance two CMVs must travel in order to crash. Also, we are trying to see how far a slower CMV must travel before a faster CMV catches up to it.

Chapter 2: One Dimensional Kinematics## Class Notes: Constant Speed

## Table of Contents

Position: where an object is located in reference to its surroundingsDistance: how far an object has traveled, regardless of directionDisplacement: how far an object is from its starting location; must have a reference point and include a directionVelocity: rate of change of position (how fast an object is going). This can be negative. Speed is the same thing, but can't be negative. Velocity must reference direction. (Measures displacement, not distance)Vectors: size and directionScalar:size onlyLesson 1: Describing Motion With WordsB,C,D

E

Speed of a Constant Motion Vehicle Lab: September 9Partner:Nicole TomasofskyPurpose:The purpose of this lab is to find the speed of a CMV, a constant motion vehicle, and see what information can be gleaned from position time graphs. Also, from this lab, I am trying to find how precisely you can measure distances with a meter stick.Objectives:Materials:Hypothesis:Data:Length of laptop = 30.0 cm

= 45.12 cm/s

The CMV moves 45.12 cm/s

Discussion questionsConclusion:For this lab, there were three objectives: How precisely can you measure distances with a meter stick? How fast does a CMV move? What information can you get from a position time graph? My hypothesis for the first question was that you could measure up to the nearest millimeter. It turns out that you can guess the distance between two millimeter marks, so you can get an even more precise measurement than I had predicted. I had also hypothesized that a CMV could travel 75 cm/s. But, my data shows that the speed of the CMV was actually 44.12 cm/s. Therefore, my hypothesis was wrong. I had also hypothesized that you could get two pieces of information from a position time graph: instantaneous velocity and average velocity. The data my partner and I collected supports this hypothesis.

There are many sources of error that could have contributed to inaccuracies. For example, the meter stick could have moved while my partner and I measured the distance between the dots. This problem could have been remedied by taping down the meter stick. Also, it was hard to get an accurate reading of the distances because the meter stick is made of wood, and the centimeter and millimeter marks do not sit directly on the page, next to the dots that my partner and I were measuring. Instead, they sit a couple of centimeters up, so depending on what angle you choose to read the measurement at, you could have different distances. Using a tape measure could have eliminated this source of error. It is important to learn how to take the proper measurements of a distance because in real life, a couple of centimeters could make a huge difference. For example, if an architect designs a building, but accidentally makes the door frames a couple of cm too small, then the doors can't fit. This would be a huge problem.

Overall, I feel that this lab was a success, and my partner and I made the best of the materials that were available to get the most accurate data.

## Class Notes: Graph Shapes (At Rest and Constant Speed)

Lesson 2: Describing Motion With DiagramsA,B,C

## Class Notes: Speed, Diagrams, Ticker Tape Diagrams

Motion diagrams show direction of velocity and aceleration

Constant speed:Increasing Speed:Decreasing Speed:## The Big Five Physics Equations (For Motion)

Lesson 3: Describing Motion with Position vs. Time GraphsLesson 4: Describing Motion with Velocity vs. Time Graphs## Class Notes: Increasing and decreasing Speed Graphs

Activity: Graphical Representation of Equilibrium## Cart and Ramp Class Activity

## Position time graph practice 9/15

average speedfor the entire 12-s?average velocityfor the entire 12-s?## Acceleration Graphs Lab: September 16

Partner: Nicole TomasofskyObjectives:What does a position time graph for increasing speed look like?What information can be found from the graph?

Hypothesis:Available Materials:Spark tape, spark timer, track, dynamics cart, ruler/meterstick/measuring tape

Procedure:c) Find the average speed for the entire trip.

Decreasing speed: distance traveled/ time elapsed = average speed

= 66.40cm/2.0s

=33.20 cm/s

Increasing speed: distance traveled/ time elapsed = average speed

=49.98 cm/1.20 s

=41.65 cm/s

Discussion Questions:For my hypothesis, I stated that you could find the instantaneous speed and average speed from a position time graph. From this lab, I learned that you can also find determine initial velocity, and average acceleration. I also hypothesized that the position time graph for increasing speed would look like a curved line with a slope that is getting steeper. The graph is also moving away from the origin. This hypothesis proved to be correct.

Tehere are multiple possible sources of error for this experiment. For example, since we had two strips of tape, maybe we got them mixed up. This could have been easily remedied by labeling the strips of tape. Also, another error that could have occurred was that our measures of the distance between the dots were inaccurate. Maybe the tape moved around while we were measuring. This could have been fixed by taping the stick to the meter stick.

## Lab: A Crash Course in Velocity

Stephanie Wang

Partner: Nicole Tomasofsky

Purpose:The purpose of this lab is to determine the distance two CMVs must travel in order to crash. Also, we are trying to see how far a slower CMV must travel before a faster CMV catches up to it.Procedure/Materials:Crashing: