Unit1_bruns

Kinematics

Vocabulary
 * ====Term ==== || ====Definition ==== || Units || Symbols || Type of Quantity ||
 * distance || * how far you have traveled IN TOTAL || meters || d || Scalar ||
 * displacement || * net/change in position relative to some origin
 * takes direction into account || meters || <span style="font-family: 'Comic Sans MS',cursive;">d || <span style="font-family: 'Comic Sans MS',cursive;">Vector ||
 * <span style="font-family: 'Comic Sans MS',cursive;">speed || * <span style="font-family: 'Comic Sans MS',cursive;">rate of change of position
 * <span style="font-family: 'Comic Sans MS',cursive;">how fast you move || <span style="font-family: 'Comic Sans MS',cursive;">meters/second || <span style="font-family: 'Comic Sans MS',cursive;">v || <span style="font-family: 'Comic Sans MS',cursive;">scalar ||
 * <span style="font-family: 'Comic Sans MS',cursive;">velocity || * <span style="font-family: 'Comic Sans MS',cursive;">includes direction
 * <span style="font-family: 'Comic Sans MS',cursive;">based on displacement
 * <span style="font-family: 'Comic Sans MS',cursive;">speed in a specific direction || <span style="font-family: 'Comic Sans MS',cursive;">meters/second || <span style="font-family: 'Comic Sans MS',cursive;">v || <span style="font-family: 'Comic Sans MS',cursive;">vector ||
 * <span style="font-family: 'Comic Sans MS',cursive;">acceleration || * <span style="font-family: 'Comic Sans MS',cursive;">how fast speed/velocity changes || <span style="font-family: 'Comic Sans MS',cursive;">m/s <span style="font-family: 'Comic Sans MS',cursive; vertical-align: super;">2 || <span style="font-family: 'Comic Sans MS',cursive;">a || <span style="font-family: 'Comic Sans MS',cursive;">vector ||
 * <span style="font-family: 'Comic Sans MS',cursive;">time ||  || <span style="font-family: 'Comic Sans MS',cursive;">seconds || <span style="font-family: 'Comic Sans MS',cursive;">t ||   ||
 * vector || * quantity
 * direction ||  ||   ||   ||
 * scalar || * only quantity no direction ||  ||   ||   ||

<span style="font-family: 'Comic Sans MS',cursive;">examples of distance AND displacement:
 * <span style="font-family: 'Comic Sans MS',cursive;"> walk 5 steps
 * <span style="font-family: 'Comic Sans MS',cursive;"> and walk back 5 steps
 * <span style="font-family: 'Comic Sans MS',cursive;"> 0 displacement and 10 steps distance

<span style="font-family: 'Comic Sans MS',cursive;">**4 types of motion**

 * Type || definition ||  ||
 * at rest || * no motion, not moving ||  ||
 * constant velocity || * no change in speed
 * covering same distance in same time || v av = d/t

|| - Instantaneous - Average
 * increasing velocity || * starting slower and steadily getting larger/faster ||  ||
 * decreasing velocity || * starting faster, then slowing down ||  ||

LAB: Constant Speed objective: What does a graph of constant speed look like? hypothesis: a line that at first gradually goes up then levels out horizontally and maintains an average speed rationale: what do you think? data and observations:

//in table headings, every column needs a label. There should be no mystery data. So each time should be labeled (trial 1, trial 2, trial 3, average time...) and the numbers at the bottom? Shallow steep what? What is that??? Graph is missing equation of the line and R 2 .//

Concluding questions: 1) Answer Objective 2) What does slope mean? 3) What r 2 value mean?

The graph is a linear function that shows the relationship between time and distance. The slope shows //where's the rest?//

Homework 6/27/11
 * 1) Summarize the Readings at the Physics Classroom directly onto your wiki.

o scalar quantity o how much ground an object covers during motion o vector quantity o how far out of place and object is relative to the original position a. What is the displacement of the cross-country team if they begin at the school, run 10 miles and finish back at the school? b. What is the distance and the displacement of the race car drivers in the Indy 500? o Scalar quantity o Rate at which an object covers distance o Fast moving object has a high speed and covers large distance in short time o Slow moving has a low speed and covers small distance in a short time o Object no movement is 0 speed o Vector quantity o Rate at which the position changes o Maximize the amount that they are displaced from original position o FURTHER
 * Mechanics
 * study of motion of objects
 * grasp concepts, not just memorize
 * Kinematics --> type of mechanics
 * describing motion of objects
 * words
 * diagrams
 * numbers
 * graphs
 * equations
 * scalar
 * quantities described by a numerical value alone
 * ignorant of direction
 * vector
 * described by numerical value and direction
 * direction-aware
 * distance
 * displacement
 * questions:
 * Speed
 * Velocity

o Must keep track of direction - where you start and where you end - time it took to get there



> o Vector quantity > o Rate at which an object changes its velocity > o Object accelerates if velocity changes > o Constant acceleration > > > Equations: The average acceleration ( a ) of any object over a given interval of time ( t ) can be calculated using the equation
 * instantaneous
 * speed at any given instant in time
 * average speed
 * average speed of all instantaneous
 * found by a distance/time ratio
 * · Acceleration
 * § Constant amount



These units may seem a little awkward to a beginning physics student. Yet they are very reasonable units when you begin to consider the definition and equation for acceleration. The reason for the units becomes obvious upon examination of the acceleration equation.



//Summaries are in your own words, but seem to be a list of definitions. Remember the purpose of the summary: to digest the information by manipulating it so that it goes into your brain and stays there! I'm not convinced that this method will have that effect. I'm also not sure about the usefulness of some of the material you copied and pasted from the P.C. I certainly don't mind if you do, but make sure that it's truly necessary and helpful, enriching your narrative.//

**Find __at least 1__ cool animation, joke, cartoon, or applet about the physics we've discussed today. Post links and a screenshot to your wiki.** > <span style="display: block; height: 1px; left: -10000px; overflow: hidden; position: absolute; text-indent: -0.25in; top: 2043px; width: 1px;"> · distance <span style="display: block; height: 1px; left: -10000px; margin-left: 1in; overflow: hidden; position: absolute; text-indent: -0.25in; top: 2043px; width: 1px;"> o scalar quantity <span style="display: block; height: 1px; left: -10000px; margin-left: 1in; overflow: hidden; position: absolute; text-indent: -0.25in; top: 2043px; width: 1px;"> o how much ground an object covers during motion <span style="display: block; height: 1px; left: -10000px; overflow: hidden; position: absolute; text-indent: -0.25in; top: 2043px; width: 1px;"> · displacement __Lesson 3: Motion Diagrams__ Change: size of velocity vector direction of vectors
 * [|A car moving at constant speed] //You need to take screenshots of these and post them, and make them into live links. Do you know how to do this?//
 * [|kinematics]
 * [|Motion with constant velocity]
 * qualitative representations
 * relative sizes and directions of velocity and acceleration


 * examples:**


 * 1. a ball thrown up into the air until the highest point**
 * 2. car driving down a hill at a constant speed**
 * 3. skier going downhill race**
 * 4. a person landing on a trampoline, sinking until stopping**

ticker tape diagram: x....x....x....x....x....x....x....x....x (constant) x..x...x......x...............x................x (increasing) x..........x......x......x...x..x.x (decreasing)

<span style="color: #8f86f1; display: block; font-family: 'Comic Sans MS',cursive; font-size: 190%; text-align: center;">__Free Fall Lab__ objective: what is acceleration due to gravity? hypothesis: gradual increase with the dots growing and getting higher 9.8m/s 2 Procedure: We cut a piece of spark tape and got onto the stool and ran our piece of spark tape through the spark timer. Before we let it free fall, we attached a 200 gram weight so that it would fall to the ground. Then, let go the weight and black dots came on it. On the table, we measured with a meter stick the dots displacement from zero.

Data Table and graph:

Analysis: The ticker tape graph shows that there is an increasing velocity. This shows that the graph is polynomial. my graph shows and accurate representation of the ticker. The graph gradually increases and it looks like it is a increasing velocity. My score of 4.62 acceleration compares very closely with the class average of 4.54. I was not that far off from the 9.8m/s 2. I had 1. 76 percent difference in acceleration and a velocity of 206.12 which was a little high. I think that the friction could have effected the way my results came out. //describe the meaning of the equation of the line. Saying "not that far off" is extremely vague... also missing %error. Where did you get velocity of 206.12? Why/how did friction affect the results?//

<span style="display: block; height: 1px; left: -10000px; margin-left: 1in; overflow: hidden; position: absolute; text-indent: -0.25in; top: 2043px; width: 1px;"> o how far out of place and object is relative to the original position <span style="display: block; height: 1px; left: -10000px; overflow: hidden; position: absolute; top: 2043px; width: 1px;">questions: Ticker tape: some tape is put through the spark timer represents different features of motion of objects Vector diagrams: direction and relative magnitude by a vector shown by a vector arrow shows velocity of a moving object during motion represented by size and arrow

V-t graphs: the slope of the line shows info about the acceleration of the object could be 0,0 or +,+ or -,- Finding slope: equation need to use the same formulas from math for triangle:b X h rectangle: 1/2b X h trapezoid: 1/2b x (h1 + h2)
 * 1) two points on the line and determine their coordinates.
 * 2) Determine the difference in y-coordinates for these two points
 * 3) Determine the difference in x-coordinates for these two points
 * 4) Divide the difference in y-coordinates by the difference in x-coordinates
 * area: showing the displacement**

- do not encounter air resistance - all accelerate at 9.8 m/s2 - known as the acceleration of gravity - depends on altitude - acceleration is given formula for determining the velocity after a falling object: vf = g * t
 * Free fall:**

4 types of equations used that are very important
 * Kinematics:**

v= velocity d=distance a= acceleration t= time

[|Free fall]
 * animations/jokes/cartoons**

__<span style="font-family: 'Comic Sans MS',cursive; font-size: 250%;"><span style="color: #00ff00; font-family: 'Comic Sans MS',cursive; font-size: 250%;">N <span style="color: #008000; font-family: 'Comic Sans MS',cursive; font-size: 250%;">e <span style="color: #ffa200; font-family: 'Comic Sans MS',cursive; font-size: 250%;">wt <span style="color: #ff00ff; font-family: 'Comic Sans MS',cursive; font-size: 250%;">on <span style="color: #f01e1e; font-family: 'Comic Sans MS',cursive; font-size: 250%;">s <span style="color: #00ffff; font-family: 'Comic Sans MS',cursive; font-size: 250%;">L <span style="color: #ffff00; font-family: 'Comic Sans MS',cursive; font-size: 250%;">a <span style="color: #0000ff; font-family: 'Comic Sans MS',cursive; font-size: 250%;">ws __ **1st Inertia:** a) an object will stay at rest b) an object will stay in motion at constant speed in a straight line c) unless forced to do something

<span style="font-family: 'Times New Roman','serif'; font-size: 18.6667px;">Force

 * ==== A __ quantity (Represented with an ** _push or pull **__**_** ) ====
 * ==== Must ** _be external to__ ** the system to cause a force (Except for gravitational) ====
 * ==== Must be caused by an object ** _in contact_ ** . ====
 * ==== Is not ** transferred_ **__ or __**__carried__** . It exists only while objects ** _ ** . ====
 * ====** Type… **==== || ====** Symbol **==== || ====** Caused by…. **==== || ====** Always points…. **==== ||
 * ====<span style="font-family: 'Times New Roman','serif';">Weight ==== || ==== w ==== || ==== Pull of earth on mass ==== || ==== Straight down ====

Kg and 9.8m/s2
||
 * ====<span style="font-family: 'Times New Roman','serif';">Friction ==== || ==== f ==== || ==== 2 surfaces rub together ==== || ==== Parallel to the surface ====

F= ϻ x N
|| <span style="color: #8e9be8; display: block; font-family: 'Comic Sans MS',cursive; font-size: 220%; text-align: center;"> Lab: Newtons 2nd law Objective: what is the relationship betweena) net force and acceleration of an object? b) mass of object and its acceleration?Hypothesis:For mass and acceleration- I believe that the bigger the mass, the more acceleration you would need. If it was smaller and less heavy, then the acceleration would be quicker.net force and acceleration- the more force, the faster the accelerationData Table and Graph:
 * ====<span style="font-family: 'Times New Roman','serif';">Normal ==== || ==== N ==== || ==== “support” force whenever 2 surfaces touch ==== || ==== Perpendicular to surface and through system ==== ||
 * ====<span style="font-family: 'Times New Roman','serif';">Tension ==== || ==== T ==== || ==== Rope or chain (pull) ==== || ==== Runs along the rope or chain away from the object ==== ||

Analysis: The force and acceleration of an object is directly proportional. There is a linear relationship. The first graph s shows that the net force and acceleration is is directly proportional. Because we know that this graph is proportional, we can see that the actual mass of .530 kg is very similar to our system mass of .5454 kg. the meaning of the equation of the line shows the .0313 y-intercept. On the first graph, there was approximately a 3 percent error. This could have been due to some of the misreadings/outliers of the acceleration reader. On the second graph, there was a proportional relationship between the total mass and the average acceleration. The average mass was .2285/m -1.227 which was the system mass over our mass that we conceived from the lab. Again, there was about a 3 percent error maybe due to miscalculations or one big outlier.

//Love the handwritten notes, and different colors. It really makes your work easy to follow and extremely clear. Good job on this lab.//

Free body diagrams Rules: - representation of all forces acting on a system- all forces are shown with linear arrows and are labeled with symbols

Newtons first law: definition: object stays at rest and an object in motion stays in motion with same same and same direction---> UNLESS acted upon by unbalanced force stationary objects and moving objects all objects resist in their state of motion eastward velocity of 5 m/s, same state of motion (5 m/s, East) leftward velocity of 2 m/s, same state of motion (2 m/s, left) state of motion of an object is stayed same unless object is not acted upon by an unbalanced force

Inertia: the resistance an object has to a change in a state of motion moving object would eventually go at rest galileo: theory:any difference between initial and final heights was due to the presence of friction if friction could be eliminated, the ball would go to the same height more inertia, more mass

if firction was eliminated, then the ball would keep going if it was there, it would still be going

state of motion: defined by velocity: objects tendency to resist changes in velocity or to resist accelerations

equilibrium: stays in the state of motion. will not accelerate
 * balanced:** equal magnitude and opposite direction
 * unbalanced:** causes accelerations for example: book to the right, slows down acceleration because it is pulling to the left, not equal magnitude and opposite direction

animation: [|Newtons 1st law] [|Newtons 1st and 2nd law] //same issue as above.//

definition: push or pull upon an object resulting from the object's interaction with another object contact forces: two interacting object look like they are physically contacting each other.
 * force: a vector quantity**
 * frictional--exerted by a surface as an object moves across it or makes an effort to move across it
 * tension--transmitted through a string, rope, cable or wire acting with an opposite force
 * normal--force exerted upon an object that is in contact with another stable object
 * air resistance-- acts upon objects as they go through the air
 * applied -- person or another object
 * spring-- exerted by a compressed or stretched spring upon any object that is attached to it


 * action at a distance forces:**result when the two interacting objects are not in physical contact with each other but still show a push or pull despite their physical separation
 * gravitational--earth moon or larger objects that gets attracted to objects
 * magnetic
 * electrical

<span style="display: block; height: 1px; left: -10000px; margin-left: 1in; overflow: hidden; position: absolute; text-indent: -0.25in; top: 2043px; width: 1px;">a. What is the displacement of the cross-country team if they begin at the school, run 10 miles and finish back at the school?b. What is the distance and the displacement of the race car drivers in the Indy 500? <span style="display: block; height: 1px; left: -10000px; overflow: hidden; position: absolute; text-indent: -0.25in; top: 2043px; width: 1px;"> · Speed <span style="display: block; height: 1px; left: -10000px; margin-left: 1in; overflow: hidden; position: absolute; text-indent: -0.25in; top: 2043px; width: 1px;"> o Scalar quanti o Rate at which an object covers distance o Fast moving object has a high speed and covers large distance in short time o Slow moving has a low speed and covers small distance in a short time o Object no movement is 0 speed <span style="display: block; height: 1px; left: -10000px; overflow: hidden; position: absolute; text-indent: -0.25in; top: 2043px; width: 1px;"> · Velocity <span style="display: block; height: 1px; left: -10000px; margin-left: 1in; overflow: hidden; position: absolute; text-indent: -0.25in; top: 2043px; width: 1px;"> o Vector quantity o Rate at which the position changes o Maximize the amount that they are displaced from original position o FURTHE o Must keep track of directio net force: vector sum of all the forces that act upon an object (if there is an acceleration at one point, there is a net force must add up the vector amounts and it shows you the net force opposite forces cancel out if its the same number, whatever is left over is the answer
 * free body diagrams:** show the relative magnitude and direction of all forces acting upon an object in a given situation

a=net force (mass to accelerate)/system mass (what is being accelerated) net force= mass x acceleration example: drop and pull

<span style="color: #33ff00; display: block; font-family: 'Comic Sans MS',cursive; font-size: 200%; text-align: center;">FRICTION

coefficient of friction: number that represents how two surfaces interact when you try to slide them across each other ratio-- no units almost always between 0-1 symbol: mu=F f / Nsurface

examples: drag something across ice- very little tires on concrete- .6 or .7 waxed skis- .3

Friction lab:

reference: see document on problems! animation: [|friction animation]

**NEWTONS 2ND LAW OF MOTION:**

behavior of objects for which all existing forces are __not__ balanced the acceleration of an object is dependent upon two variables net force acting upon the object and mass of the object force acting upon an object is increased, the acceleration of the object is increased mass of an object is increased, the acceleration of the object is decreased.

Fnet= m * a, **a = Fnet / m** shows the net force
a=fnet/m gravitation force= m x g (mass x gravity)

system analysis :usually performed to determine the acceleration of the system, combined with individual object analysis: either one of the two objects is isolated and considered as a separate, independent object

dynamic equilibrium a=0 terminal velocity

**NEWTONS 3RD LAW:** every action has an equal and opposite reaction meaning: force is not conserved, but energy is cannot be contact between 2 things without those 2 things touching each other all forces come in pairs, that equal in size, pointing in opposite directions, acting on 2 separate systems

for example: elevator scale truck hitting a beach volleyball

at woods machine: 2 pulleys

difference in wights create accelertion a= l mass2g - m1g l /m1 + m2
 * analysis: **

<span style="color: #00a8ff; display: block; font-family: 'Comic Sans MS',cursive; font-size: 180%; text-align: center;">** DROP N PULL LAB: **

Calculations: result: 1st trial- .89 2nd trial- .856 3rd trial -.8293
 * Question: how much mass should you hang to make the cart move .8 m in __s?**
 * percent error**
 * list causes of error**


 * Vector diagrams --- vector by use of an arrow drawn to scale in a specific direction
 * a scale is clearly listed
 * vector arrow- drawn in a specified direction: vector arrow has a head and a tail
 * the magnitude and direction of the vector is clearly labeled
 * north south east west, showing ah ead
 * direction with degrees
 * SOHCAHTOA - to find out length of vector or inverse for angle
 * Pythag. Theorem to figure out the length of angle
 * Resultant: vector sum of 2 or more vectors
 * http://zonalandeducation.com/mstm/physics/mechanics/vectors/componentAddition/componentAddition2.htm


 * Newtons 3rd law: **
 * for every action, there is an equal and opposite reaction
 * action reaction force pairs
 * equal (in size) and opposite (in direction) reaction
 * [|Newtons 3rd law]

<span style="color: #0094ff; display: block; font-family: 'Comic Sans MS',cursive; font-size: 250%; text-align: center;">**Projectiles:** definition: an object that is acted upon only by gravity, must be moving in 2D launching horizontal shows that the angle is 0 degrees practice:

<span style="color: #ff00ff; display: block; font-family: 'Comic Sans MS',cursive; font-size: 33.6px; text-align: center;">**PROJECTILE MOTION LAB:** Data and calculations:

<span style="color: #00a8ff; font-family: 'Comic Sans MS',cursive;">**Initial velocity using projectile motion**


 * discuss independence of x and y axes**

Homework 7/5/11 **What (specifically) did you read that you already understood well from our class discussion? Describe at least 2 items fully.**

A projectile is an object upon which the only force acting is gravity. Gravity is the single force acting upon the object. Gravity on the free body diagram is always pointing down. An object at rest, thrown upward, and an object thrown at an angle to be horizontal all depict projectile motion. **Vx**shows the velocity in displacing the projectile horizontally. For Vx, you use Vxcos theta **Vy** describes the influence of the velocity in displacing the projectile vertically. For Vx, you use Vy sin theta. By using this, you can solve projectile motion problems with the trigonometric methods.

**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.**

At first, I didnt understand how you would set up each of the equations. But as I read along, and saw the different examples and equations used, I got a better understanding on how to use the equations. Specifically, the main equation used is d= Vixt + 1/2at^2 which is also used for the y. **What (specifically) did you read that you still don’t understand? Please word these in the form of a question.** Nothing. **What (specifically) did you read that was not gone over during class today?**

Projectiles travel with a parabolic trajectory. Downward force and acceleration shows a downward displacement from the position that the object would be without gravity. The force of gravity does not affect the horizontal axis, there is a horizontal velocity.

animation: [|projectile motion animation and questions]

<span style="color: #00fff2; display: block; font-family: 'Comic Sans MS',cursive; font-size: 190%; text-align: center;">**F<span style="color: #ff00ec; font-family: 'Comic Sans MS',cursive; font-size: 190%;">oR ce<span style="color: #8e9be8; font-family: 'Comic Sans MS',cursive; font-size: 190%;">S <span style="color: #33ff00; font-family: 'Comic Sans MS',cursive; font-size: 190%;">in 2D** <span style="color: #00fff2; display: block; font-family: 'Comic Sans MS',cursive; font-size: 190%; text-align: left;">

<span style="color: #ffd700; display: block; font-family: 'Comic Sans MS',cursive; font-size: 200%; text-align: center;">Lab: Acceleration on Incline

<span style="color: #ffd700; font-family: 'Comic Sans MS',cursive;">**Question:** What is the relationship between acceleration of an object and angle of the incline <span style="color: #ffd700; font-family: 'Comic Sans MS',cursive;">**Hypothesis:** I believe that with the angle of incline being higher, the acceleration is going to be faster. If the angle of the incline was lower, than I believe that the acceleration is going to be slower. Since we are starting from a steep incline, the acceleration is going to be quicker than if the incline was smaller. <span style="color: #ffd700; font-family: 'Comic Sans MS',cursive;">**Analysis:** <span style="color: #ffd700; font-family: 'Comic Sans MS',cursive;">**what is the relationship? Answer objective with evidence.** The relationship between the acceleration between sin theta and acceleration show a linear relationship. The cart shows every time there is an increasing acceleration the platform increased and the sin theta started to increase. For example, when the acceleration was .3386 m/s2, the sign theta was .0346. When you look at a higher height such as .138, the acceleration was quicker at 1.1128 m/s2 and the sin theta also increased to .1136. <span style="color: #ffd700; font-family: 'Comic Sans MS',cursive;">**Experimental error and way to eliminate if we redo lab.** There are a few experimental errors. Of course, there is human error. For example, somebody could not have timed correctly. Also, the data could be entered incorrectly. When letting the cart go, the person could have moved it closer or farther from the starting to point changing the times. If we redid the lab, we could have the photogates give us a specific time. Also, we could have the starting point very precise to know that we didn't move the cart forwards and backwards from the starting point.
 * <span style="color: #ffd700; font-family: 'Comic Sans MS',cursive;">Data and Calculations: **

<span style="font-family: 'Comic Sans MS',cursive; font-size: 210%;"> Newtons Law of Universal Gravitation (L <span style="color: #ff00c7; font-family: 'Comic Sans MS',cursive; font-size: 210%;">UG)

every object is gravitationally attracted to every other object gravitational force is equal to the product of the masses gravitational force is inversely proportional to the square of the distance distance is center to center Mass of earth= 5.98 x 10 24 Kg radii of some objects may be negligent Fg= G( universal gravitational constant) m1 x m2/d 2 G= 6.67 x 10 -11 Nm 2 /kg 2

Cavendish & Von Jolly force of gravity, gravitational force and gravitation attraction, weight are ALL THE SAME practice: <span style="color: #8f86f1; display: block; font-family: 'Comic Sans MS',cursive; font-size: 240%; text-align: center;">**Keplers Laws** Law of elipses- planets move in elliptical orbits around sun with the sun at one focus. Eccentricity is how far from a circle the orbit is law of equal areas- the area between the two points is equal to the area between 2 points if the time elapsed is the same (closer to sun, faster movement) law of harmonies- the period squared over the radius from the sun cubed is the constant that is the same for all planets in our solar system

<span style="color: #ff0500; font-family: 'Comic Sans MS',cursive; font-size: 170%;">Homework Lesson 13 and 14 **Addition of forces headline:** The head to tail vector addition applies to the addition of vector forces. Using a force board helps with the addition of force vectors. It has chains or cables giving off forces upon the center ring in 3 different directions. A force boar helps figure out the amount of force in each direction and determines the vector sum of 3 forces. Perpendicular forces are usually ignored in the analysis.

**Resolution of forces headline:** A single force can be resolved in 2 components. For example, the vertical components shows the upward influence of the force. The horizontal component show the rightward influence of the force. Most important, only the angle with the horizontal is changing. if the angle increases, the force in horizontal direction decreases. When there is less force being allowed, the less influence there is in the horizontal direction. **Equilibrium and statics:** Objects at equilibrium must have an acceleration of 0 m/s/s. This relates to Newtons first law of motion. You also must use SOHCAHTOA to solve problems. By using the trigonometric equations show an angle with the horizontal increases, the amount of tensional force required to hold the sign at equilibrium decreases. **Net force problems revisited:** You need to determine acceleration by first determining the net force by adding up all the forces as vectors and then dividing the net force by the mass to determine the acceleration. Most importantly, you need to know about the problem that the normal force is not necessarily equal to the gravitational force. The vertical forces must balance if there is no vertical acceleration. If an object is being dragged across a horizontal surface, then there is no vertical acceleration. If there is an acceleration for an object being pulled across a floor, there is a horizontal acceleration. **Inclined Planes:** There are 2 forces- the force of gravity and the normal force. A tilted surface is called an inclined plane. Objects are known to accelerate down inclined planes because of an unbalanced force. The normal force is not directed in the direction that we think it is. **Gravity is more than a name:** force that exists between the Earth and the objects that are near it which is known as the force of gravity. The acceleration of gravity is the acceleration experienced by an object when the only force acting upon it is the force of gravity. **The apple, the moon and the inverse square law:** the law of ellipses is the paths of the planets about the sun are elliptical in shape, with the center of the sun being located at one focus. The law of equal areas is an imaginary line drawn from the center of the sun to the center of the planet will sweep out equal areas in equal intervals of time. Finally, the law of harmonies is the ratio of the squares of the periods of any two planets is equal to the ratio of the cubes of their average distances from the sun. **Laws of Universal gravitation:** The gravitational force is directly proportional to the mass of both interacting objects, more massive objects will attract each other with a greater gravitational force. The gravitational force is inversely proportional to the separation distance between the two interacting objects, more separation distance will show gravitational forces. <span style="color: #ff00d3; font-family: 'Times New Roman',Times,serif; font-size: 110%;">**Cavendish and the value of g:** Cavendish's experiment shows the a light, rigid rod about 2-feet long. Two small lead spheres were attached to the ends of the rod and the rod was suspended by a thin wire. When the rod became twisted, the torsion of the wire begins to exert a torsional force that is proportional to the angle of rotation of the rod. This helped see the constant of proportionality in the equation is G (universal gravitation constant). **The value of g:** The value of G is independent of the mass of the object and depends upon location - the planet the object is on and the distance from the center of that planet. animations/joke/cartoon: [|universal law of gravity] [|2D force]

<span style="color: #00ffac; display: block; font-family: 'Comic Sans MS',cursive; font-size: 280%; text-align: center;">**Circular Motion**


 * 2D dynamics --> constantly changing the direction your going in
 * accelerating
 * CHANGING VELOCITY--> changing SPEED and DIRECTION
 * uniform circular motion (UCM): constant speed but changing direction
 * **NO KINEMATICS EQUATION**
 * a (centripetal acceleration)c = (speed)v 2 / R (radius)
 * Centripetal force: causes an object to move in a circle
 * examples:
 * what is the tension in a string on a 1.2 kg ball moving in a .75m radius circle at 2m/s ?
 * if max tension string could manage 50 N, Vmax= ?

<span style="color: #a600ff; display: block; font-family: 'Comic Sans MS',cursive; font-size: 220%; text-align: center;">Lab: Min/Max Velocity <span style="color: #000080; display: block; font-family: 'Comic Sans MS',cursive; text-align: left;">Part A: find max tension of string at static equilibrium <span style="color: #000080; display: block; font-family: 'Comic Sans MS',cursive; text-align: left;">Part B: find min v at top of loop <span style="color: #000080; display: block; font-family: 'Comic Sans MS',cursive; text-align: left;">Part C: find max v at bottom of loop <span style="color: #000080; font-family: 'Comic Sans MS',cursive;">Data and Calculations :

<span style="color: #000080; display: block; font-family: 'Comic Sans MS',cursive; text-align: left;">Analysis: calculate Vmin and Vmax and compare experimental values The experimental error for this lab was very high. Looking at the values, there wasn't really an accurate reading we could derive because the experimental error was so high. The velocity minimum was 3.559 m/s and the velocity maximum was 8/335 m/s. Compared to the theoretical values, the minimum of our 3.559 m/s and the theoretical which was 2.21 m/s was very different. This shows that the way we did the experiment was not accurate and were not close to the theoretical value. The experimental maximum of 8.335 m/s and the theoretical which was 21.11 m/s shows a really big difference in the velocity's. the times were all over the place and so were the number of periods we got for each time. <span style="color: #0022ff; display: block; font-family: 'Comic Sans MS',cursive; font-size: 220%; text-align: center;">Lab: Conical Pendulum question: what happens to the period when you increase the radius of a conical pendulum? hypothesis: As the radius increases, the theoretical period and average experimental decreases Data and calculations: Example of theoretical period calculation for .10 meters: analysis: There were a couple sources of error. For example, the centimeters could have not been exact. Second, somebodies reaction time with a timer could not have been the same as another persons. Also, it depended on where you were sitting around the conical pendulum. Not everyone's point of view was the same as another persons. Although, this data shows an inverse relationship. As the radii meters increased, the theoretical periods decreased.

<span style="color: #e10847; font-family: 'Comic Sans MS',cursive; font-size: 180%;">Lesson 15 and 16 homework: The distance of one complete cycle around the perimeter of a circle Average speed= distance/time=circumference/time Average speed= 2(pi)r / t Circumference= 2(pi)r R- represents to radius t- represents the period It’s always going to be tangent to the circle going in a straight line It is called an accelerometer. An accelerometer consists of an object immersed in a fluid such as water. For example use sealed jar that is filled with water. A cork is attached to the lid by a string can be the accelerometer. To test the direction of acceleration for an object moving in a circle, the jar can be inverted and attached to the end of a short section of a wooden 2x4. some physical force pushing or pulling the object towards the center of the circle Work = Force * displacement * cosine (Theta) Away from the center or outward ANIMATION: [|uniform circular motion- centripital force]
 * What is circumference?**
 * What is the circular motion average speed equation?**
 * What is the circular motion circumference equation?**
 * What does R and T represent?**
 * What direction is the velocity vector always going to be?**
 * What is acceleration measured with and how?**
 * What is a centripetal force?**
 * What is the amount of work done on an object equation?**
 * What is centrifugal?**

A clothoid is a section of a spiral in which the radius is constantly changing. The radius at the bottom of a clothoid loop is much larger than the radius at the top of the clothoid loop. The radius of these circular sections is decreasing as one approaches the top of the loop. If a passenger was on a roller coaster, she would feel an acceleration due to both a change in speed and a change in direction. The acceleration can be described as being centripetal or towards the center of the circle. There would be an inward acceleration and the inward direction being towards the center of whatever //circle// the object is moving along. There would also be a centripetal force for such a motion. The contact force balances the downward force of gravity and meets the centripetal force requirement for an object in uniform circular motion.
 * What is a clothoid loop?**
 * What happens if the speed is constant on a roller coaster?**
 * How do you make a turn and manage not to fall?**
 * When there is a component of force directed towards the center of the circle about which the person is moving.**
 * What kind of acceleration and direction would there be with an object going around a circle?**
 * What does contact force do?**

Animation: [|Circular motion animation]

<span style="display: block; height: 1px; left: -10000px; overflow: hidden; position: absolute; top: 21298px; width: 1px;">I really hated method 2. It was the same by picking out most of the main ideas from each page and some important aspects of the topic. But, it was different because I felt like I included a lot more information and I had to really look for what I was going to put into my “headline”. The pros of the headline method are that you take away the main idea and main aspects of each topic. The cons are that you always still will have a little bit more information missing. If forced me to handle and find the material used in my headline, but I feel like I remember more from the reading.