Ch2-KistB

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= Bryan Kist's Wikilog - Period (6) CP Physics - (E. Burns) - 2010 = toc

=Section 1=

Reference to Sports Science In my article I found how that the torque from a golf swing isn't all from the back but it is from the torque from the hips as well. "When the results were analysed, significant correlations were found between club-head angular velocity at the moment of impact with the ball and left and right maximum hip moment. What's more right-hip torque was significantly correlated to swing intensity both at the top of the backswing and at mid-downswing showing that the right hip is instrumental in initiating and driving the downswings that achieve the greatest distance and so suggesting new avenues for both research and coaching."

Sources- http://www.sciencedaily.com/releases/2010/09/100907071427.htm

What do you see/think? What do you see - The kid who is running at the ball kicked it much farther than the kid who was standing still. The more momentum you have the farther something will go you exert the force on it. What Do You Think - figure skaters keep in motion by taking long strides that keep them in motion, also the skater is on ice so there is little friction to slow the skater down, once a skater accelerates to a certain velocity their mass allows them to stay in motion. After a soccer ball has been kicked it does not lose its momentum right away because it is in the air, also the shape of the soccer ball will keep it rolling and it will not stop right away.

Investigation X1 1E- The Vertical Height of the top of the left track it 5.6 meters, and the opposite side is 5.48 meters 2A/E- He will return to the same spot because one end of the track is steeper than the other and he will not go as high, but on the other side he will go the same wven though it is less steep he will go the same height. 3A- My predictions were about .2 meters off because I may have not measured correctly. 3B- the height will be the same because he does not build up much speed from the less steep slope but will 4A- The height is lower but it is equal to the other height because as he gains the speed from the less steep slope he will not travel as high on the steeper slope. 4B- My predictions were accurate because for each trial it was a different height, but within each trial the height was the same. 5A- No matter how high he travels he will never recover his starting height because he loses momentum. 5B- He would roll as far as he will until the momentum is lost. 5C- Gravity would keep the roller on the horizontal track. 5D- He does what I thought he would do because he never regains his starting position. 6A- The opposite track gets steeper 6B- It stays the same because he does not travel as high on the steeper track 6C- The vertical height is lower but it is the same within each trial 6D- The skater would stop when his momentum does

Physics Talk - Inertia is a property of matter which measures the resistance to changes in motion. - Mass is how we measure an objects inertia. Kg's is the base unit for Mass. - Weight is how much gravity pulls on a mass - Galileo's experiment is all theoretical and ideal because there is no friction, but in real life there is friction. - Law of Inertia- Inertia is the natural tendency of an object to remain at rest or to remain moving with constant speed in a straight line. - Newton’s first law of motion: In the absence of an unbalanced force, an object at rest remains at rest, and an object already in motion remains in motion with constant speed in a straight-line path. - Velocity is speed in a given direction. - Sometimes speeds are constant. These motions are examples of Newton’s first taw: Objects in motion (at constant speed) stay in motion (at constant speed) unless a force acts on them. When a force acts, the speeds change. This change in speed during a specific time is referred to as acceleration. - frame of reference: a vantage point with respect to which position and motion may be described. It all depends on your frame of reference and how you see things.

Checking up 1. Inertia is the natural tendency of an object to remain at rest or to remain moving with constant speed in a straight line. 2. Newton’s first law of motion: In the absence of an unbalanced force, an object at rest remains at rest, and an object already in motion remains in motion with constant speed in a straight-line path 3. An outside force such as a pull, push, or any outside force acting upon the object will stop it from moving at a constant speed. 4. An unseen force of friction willl stop the ball from rolling forever. 5. The object with a greater mass will have a greater inertia, 6. it is important to establish a frame of reference because the ball can be seen as moving at two speeds depending on your frame of reference.

Physics To Go 1a/b- The ball will go forever because there is no friction which means there is no force that is acting upon it. 2- The ball will reach 20cm on the opposite side because it will reach its exact starting height on a frictionless surface. 3. No because no matter what surface you roll something on, there will always be friction which will make the object stop. 4. the hockey puck will slow down because even though ice is a slippery surface, there is enough friction to slow it down before it hits something. 5. 4.5m/s+2.5m/s= 7m/s 6. 10.3m/s+4.2m/s= 14.5m/s 7a. 5.6m/s+2.4m/s= 8m/s 7b. 5.6m/s-2.4m/s= 3.2m/s 7c. 6.1m/s- do inverse Tangent 8. 85m/s-18m/s= 67m/s 9a. 15cm/sin(45)= 21.21cm b. 15cm/sin(20)= 43.86m/s c. 15cm/sin(15)= 58cm d. 15cm/sin(5)= 172cm 10a. There is 4 seconds left in the game, the quarter back takes a running start and throws a bomb!!!!! since he has a running start the ball will travel faster and farther. In ice skating there is less friction between the person and the ice so it will be easier for them to accelerate and maintain their velocity. In soccer, goal kicks usually start with a running start in order to kick the ball faster than you would without a running star.

What Do You think Now? Ice skaters stay at high speeds for sustained amount of times because ice is a low friction surface meaning that once they get going it is hard for them to stop which is an example of inertia. Since ice skaters have a higher mass then most smaller objects, they have a greater inertia. Soccer balls continue to roll down the field because it is a round object on a flat surface and there is little friction so it will continue to roll.

Inquiring Further 2. In the sport of baseball people slide into base in order to avoid being tagged out, but they don't slide into first base because once you touch the base you are safe even if your run through. Newtons first law say that things will slide forever without friction but because there is friction between the player and the ground will mean that they stop in time to be on the base, without over shooting the base.

= ﻿Section 2 =

What do you see? What do you think? - In the first picture the boy is walking slowly taking his time because he is not thinking of anything so his strides are smaller. But when the boy is thinking of love he is running and taking larger strides than he was when thinking of nothing. - The two terms 100m/h and 45 m/s on first glance really mean nothing to me, at first one would think that 100m/h is much faster than 45m/s but upon research 45m/s is just about 100m/s.

Physics talk - Acceleration- a change in velocity with respect to time - When a person was at constant speed, the distance between the dots on the tape were equal, but when you were accelerating th dots got farther apart as you increased speed, and when you slowed down, the dots got closer together. - Average speed is calculated by distance travelesd divided by the time elapsed. - The reading of your speedometer at any given point during the trip, is your instantaneous speed. - Acceleration is calculated by the change in speed divided by the time interval.

Checking up 1. At constant speed, the dots on the tape would be at equal intervals, accelerating the dots would be closer and then get farther apart as the tape goes faster, and when the tape is negativeley accelerating the dots are farther apart af first and get closer as it slows down. 2. the runners average speed would be calculated by 400m/50s= 8m/s 3. instantaneous speed is your speed at one given point of the entire trip, average speed is your average speed for the entire trip. 4. the vehicles acceleration would be calculated by 100km/h divided by .0028= 2.8m/s^2

Physics to Go 1. Average speed is the average speed of the entire trip, and instantaneous speed is your speed at any one point of the entire trip. 2a. 1km=1000m, so 1000m/15s= 66.67m/s 2b. 84m/6s= 14m/s 2c. 9.6km= 9600m, and 2hrs= 7200s, so 9600m/7200s= 1.33m/s 2d. 4.5hrs= 16,200s and 400km= 400,000m, so ﻿400,000m/16,200s=24.69m/s 3a. when a runner falls down he is negatively accelerating. 3b. The runner is gaining velocity so it is posotive accelration. 3c. No acceleration is occuring. 3d. when a ball is stopped it is negative acceleration 3e. No acceleration is occuring 3f. No acceleration is occuring. 4a. Both graphs A and D represent a constant increase in speed because the length of the tape is gradually increasing by the same amount every time. 4b. Graph B represents a student with constant motion because the lengths of each strip is the same. 4c. A because the difference between each piece of tape is the greatest. 4d. Graph C represents a student that was increasing speed then later decreasing speed. 4e. Graph A is positive, Graph B is nothing, Graph C is positive, Graph D is positive. 14a. A Marathon runner in the middle of the marathon. 14b. A sprinter toward the end of his sprint. 14c. The curling rock after a throw 14d. An NBA player during a fast break. 14c. An NFL player slowing down going into the End Zone.

Physics To Go #6-11 6. -12.5m/s /9s= -1.4m/s b. Negative





What Do You Think now? 100mi/h and 45m/s are two completely different terms in my eyes after what we learned. Before when i investigated they are both about the same speed but now 100mi/h is in terms of miles and hours when 45m/s is in termsof meters and seconds which are completely different and almost uncomparable.

Reflecting on the Section and the Challenge The runners are almost at the 3 mile mark and several are still running strong. The man in first place is going a steady or constant speed of 9m/s, this means in every second he will go exactly 9 meters. The 2 runners behind him are battling for 2nd and 3rd place, runner number 2 is slowing down or negatively accelerating to give runner number 3 the 2nd place spot. Runner number 4 shows a quick burst of speed and passes runner number 2 by positively accelerating until he was infront of him.

Physics Plus for Section 2





= Section 3 =

What Do You see? The boy is speeding up and is trying to keep the ball against the stick even though it is very hard to do.

What Do you Think A force is something that you make in order to make something move, such as a push or a pull. The tennis ball and the bowling ball will have the same amount of force because even though they are different masses they both have much force.

Section 3 investigate

2a. The cart is moving at a constant speed. 3a. The Cart is going at a faster constant speed. 3b. They are both moving at a constant speed 3c. The one with the larger bend went at a faster speed because there is more force involved. 3d. The greater the constant force pushing on an object, the greater the acceleration during the same interval of time. 4a. Since the bottle is significantly lighter, less force is necessary to push it. 5a. When we pushed the water bottle with some liquid in it, there was a greater mass so it needed more force to push. 5b. When equal amounts of a constant force are used to push objects using different masses, the more massive object doesn't have as much acceleration as the lighter objects. 6a. The conclusion that we drew that weight and mass are important in the force needed to move the object. 8a. The ruler bends 9a. Each time you add a coin the ruler bends more and more until the coins fall. 9b. One penny represents a small force and 2 represent a large force. 9c. The weight of the coins

Physics Talk - Newtons second law can also be written as Acceleration= Force Divided by Mass, a=F/m - Force is expressed in Newtons, a Newton is a Force required to make 1kg of mass accelerate to 1m/s^2 - Accelerations are caused by unbalanced forces - Newtons Second Law relates force, mass, and acceleration - Newtons second Law states that the acceleration of an object is directly proportional to the applied forca and inveresely to the mass. - All non zero digits are significant figures - Zeros are non significant unless they are put inbetween 2 numbers - Zeros at the end of a decimal number are considered significant - Zeros at the beginning of decimal numbers are not significant - In large numbers without decimal points, the zeros are not significant - Weight is the verticle downward force exerted on a mass as a result of gravity. - Free body diagrams are diagrams showing the forces acting on an object - If the opposite forces acting upon an object are equal the object will not move.

Checking Up 1. Newtons fist law tells us that force is equal to mass times acceleration 2. The heavier the mass of an object the slower the acceleration will be, the lighter the mass the faster the acceleration will be. 3. One Newton is the force required to accelerate 1kg to 1m/s^2, so 30N would mean that the object weighs 30kg 4. you weight would decrease and your mass would stay the same

**Physics To Go**

1.
 * Newtons Second Law || Force= || Mass x || Acceleration ||
 * Sprinter at beginning of 100m dash || 350N || 70kg || 5m/s^2 ||
 * Long Jumper in Flight || 800N || 80kg || 10m/s^2 ||
 * Shot-Put ball in flight || 70kg || 7kg || 10m/s^2 ||
 * Ski Jumper going downhill before the jump || 400N || 80kg || 5m/s^2 ||
 * Hockey Player "Shaving Ice" while stopping || -1500N || 100kg || -15m/s^2 ||
 * Running Back Being Tackled || -3000N || 100kg || -30m/s^2 ||

3. a=F/m, a=42N/.3kg= 140m/s^2 4. F=ma, F=(.040kg)(20m/s^2), F= .8N 5a. since the bowlingball has a greater mass, it has a greater inertia making it harder to stop 5b. Since the Bowling ball has a greater mass and the same acceleration which means it has a greater Force making it harder to stop. 9. Side one has a compined mass of 400kg and an acceleration of .6m/s^2, side 2 has a combined weight of 450kg, and a acceleration of .4m/s^2, side one has a Force of 240N and side two has a force of 180N, Since side one has a greater force they will win the Competition!!! 10. The unbalanced force is 90N because the 2 forces are not equal 11. 200Nx4= 800N, the total force is 200N times the 4 guys pushing on the car 12. a=F/m, a= 125N/700g, a=.179m/s^2 15. F=ma, so F=9.8m/s^2 x 12.8kg, F=125.44N

#'s 13, 14, 16, and 17

Physics Plus Pg-169



=Section 4=

What Do you See? what Do You think?

- The the What do you see there is a girl throwing 2 apples, she is dropping one straight down and trowing one out. The boy down below is timing both throws - What Do you Think- The determining factors on how far the ball is going could be how much force you put into it, the angle of the throw, and the weight of the object all effect how far a object will go before landing

Physics Talk - Trajectory is the path in which an object travels - Projectile is an object acted on only by gravity - The x-component and y-component of all vectors are independent meaning that X-components are only effected by X-components and Y-components are only effected by Y-components. - The time it takes a horizontally launched projectile to hit the ground is the same as the time it takes to drop - Acceleration due to gravity is -9.8m/s^2 - Vertical velocity changes by 10m/s every second - Horizontal Velocity never changes in a projectile - Vy is always zero at maximum height

Checking up 1. They hit the ground at the same time if there was no air resistance, air resistance is the only factor that changes the hang time of a horizontal launch 2. It changes by about 10m/s every second 3. Its velocity is 0m/s, and the acceleration is -9.8m/s^2

Physics To Go 4. Everyboy thought that the bullet that was shot horizontaly would hit the ground first until i explained to them that horizontal velocity has no Effect on the projectile 6. A projectile's horizontal motion has no effect on its vertical motion, and a projectiles vertical motion has no impact on its horizontal motion. Vertical velocity changes by -10 m/s every second. Horizontal velocity never changes. Diagrams greatly display this by the stair case view. 7. taking out the factor of air friction, the arrow that is being dropped and the other arrow being shot horizontally at 50m/s will land at the same time, due to gravity. 8. c=3.6 at 33.7 degrees 9a. 11.98m/s 9b. 23.96 m 10a. 8.5m/s 10b. 4.25m

Physics Plus

What do you think now? In order to determine how far an object will move while in the air, you need to measure/determine launch velocity and initial height. When your launch velocity is increase/decreased, and when your initial height is increased/decreased. As the initial height increases, the range increases. The relationship between launch velocity and initial height is valuable information.

= Section 5 =

What do You See?

there is a ball being kicked up, and then falling down, bouncing off of a kids head then falling down

What do you think?

1. smaller angles have long ranges velocities and are up for a shorter amount of time larger angles have smaller rangers and are up for longer amount of time 2. The greater the speed, the faster the object will travel, so the range will be longer.

Physics Talk

- when you count out air resistance, the shape of all trajectories are parabolas - A launch at 45 degrees produces the greates range - Distances traveled at 30 and 60 degrees, 20 and 70 degrees, and 10 and 80 degrees all have the same range. - Small angles have greater horizontal velocities but are in the air a short time - Large angles have smaller horizontal velocities but are in the air for a larger amount of times - In the real world, things do not travel in true prabolic paths because of air resistance.

Checking up Questions 1. Constant motion and downward acceleration at -9.8m/s^2 2. They must make sure that their proposal matches reality in nature 3. If 2 projectiles are launched at 2 different angles, and these 2 angles add up to 90 degrees then they will have the same range

Physics To Go 1. The angle that produces the greatest range is 45 degrees because it is directly between the horizontal and verticle paths. 2a. If the angle is greater than 45 degrees, the projectile will spend more time in the air 2b. If the angle is less than 45 degrees, it will spend less time in the air. 3a. 60 degrees will produce the same range as 30 degrees 3b. 75 degrees will produce the same range as 15 degrees. 4. The reason that this occurs is because humans are not powerful enough to create such a trajectory 5. He was most likely powerful enough to create larger launch angles and produce a greater range 6a. -9.8m/s^2 downward 6b. The direction of the balls velocity is east 7a. W=mg= 29.4m/s b. 5m/s c. 15m (work for #7)



8. closest to 45 degrees 9. the one closest to 90 degrees 10a. down b. 4.5s c. Dx=VaT+1/2aT^2 = 90m (work for #10)



Physics Plus #1,2



= =

What Do You Think Now 45 degrees produces the greatest range, anything more produces greater air time, but a shorter distance. If two launch angles are complementary such as (30-60 or 35-55) they will have the same range.If a projectile is launched at a greater velocity and the same angle it will go farther.

= Section 6 = = = What do you see/think now? - In the what do you see there is a boy who is on a chair and pushes off the wall. because the wall pushes back with a greater force he rolls away from the wall. - If i was telling someone to jump i would tell them to push with as much downward force as possible, they would then jump into the air because the earth pushes back with the equivalent force of his jump just in the opposite direction.

Physics Talk - Newtons third law states that for every force, there is an equal and opposite force, the two forces always act on different objects. - For example- When you walk you push backwards, but the floor pushes you forward with an equal amount of force. - Force always comes in equal and opposite pairs - Free body diagrams are diagrams that show forces that are applied or acting on an object - The weight of an object can be represented by an arrow drawn through the center mass - Newtons 3rd law can be described in 3 different ways 1. For every force applied to object A by another object B, there is an equal and opposite force applied to object A and B 2. If you push or pull on something, that something pushes or pulls back on you with an equal amount of force in the opposite direction 3. Forces always come in Pairs

Checking up Questions 1. Newtons third law says that for every force applied to an object, there is an opposite and equal force put back on the object. 2. The equal and opposite force would be the earth, if this force was less than the force of gravity we would fall straight through the Earth 3. A free body diagram shows the forces that act upon an object using arrows.

Physics To Go 1. The shot put ball pushes back but the force of the arm is greater than the force of the ball so it goes flying. 2. Chairs bend slightly when sat on and they are always pushing up even when no one is sitting on them, they just push on the air that is above them. 3. The bathroom scale measures your weight by measuring the forces that are pushing down on you 4. Many times the bat exerts a greater force than the ball which is why the ball goes flying, sometimes the way the bat is swung and how fast the pitch is the force exerted on the bat is more than it can handle so it breaks. 5. The Bigger football player has a greater mass and more force compared the the smaller football player who has less mass and less force 6. The boards push back with an opposite and equal force than that of which the hockey player hits is, therefore the hockey player stops 7. Base ball players use the gloves because you can put force on the entire glove making it easier to catch. 8. Here, Ray Allen is showing us his superior three point shooting skills. As he releases the ball, it is exerting a force back on the force he is putting on the ball, he has to exert just the right amount of force for the ball to go into the basket, HE HIT THE 3 POINT BUZZER BEATER FOR THE WIN!!!!!! The way that I made this more exciting is that it was like a sports announcer actually narrating the game.

What do you think now - the way that i would describe it is that you would have to push down with a force and the ground will push back with an opposite and equal force. The reason that you would have to push down is that since the force the ground applies to you is opposite to the force you apply it will propel you up.

= Section 7 =

what do you see/think - he is pulling a pair of shoes on ice and then she is pulling them on the sand and having a hard time moving them - Some sports require special shoes in order to make it easier to move and to get better traction, spikes for cleats make it easier to get traction on the turf, and the blades on skates make it easier to glide across the ice.

Physics Talk Friction Analyzing the Forces Acting on the Shoe -friction: a force that resists relative motion between two bodies in contact -2nd law: vertical forces on the shoe must add up to zero The downward force of gravity on the shoe must be the same as the upward force applied to the shoe by the surface normal force: the force acting perpendicularly or at right angles to a surface coefficient of sliding friction: a dimensionless quantity; its value depends on the properties of the two surfaces in contact and is used to calculate the force of friction -the force of friction is = force required to slide the oject on the surface with a constant speed coefficient of sliding friction = Ffriction / Fnormal -no units because it is a force divided by a force -expressed in decimals -valid only for the pair of surfaces in contact when the value is measure -if a surface were tilted or if the pulling force were angled up/down, the force exerted by the surface on the object would be harder to determine

Checking up 1. The force of friction is equal to the force being recorded on the scale, this is because the force of the spring is opposite of the friction. 2. it has not units because its a force divided by a force so they cancel eachother. 3. the force of friction is the force required to move that object at a constant speed.

Physics To Go 1) In basketball, you want to have better traction in order to keep your footing. if it is wet or icy you would want more friction between the court and the shoe so you would not slide around. 2) In skating they wear blades in order to reduce friction and making gliding across the ice easier. 3) No, because other courts may be a different material or it may not be as waxy. 4) Tennis players have different shoes for clay, grass, and hand surfaces. For the hard surfaces, their shoes need to provide more friction. On the clay courts, which are more slippery, the shoes need to provide more friction & have a good grip. For grass, the shoes need to provide less friction so they can slide and get to the ball easier. 5) .03=x/600N= 18N in order to move it at a constant speed 6a) W=mg=1000(9.8)= 9800 6b) µ=F/N- .55=f/9800= 5390=f 6c) Fx=max= -f=ma= -5390=1000a, a=-5.93m/s^2 6d) Vf=Vi+at, 0=Vi+(-5.39)(6), Vi= 3.34m/s 7) air resistance changes because the faster you travel the more air resistance changes it depends on the speed 8) If there is a max it sets a limit even if you have strong legs, its however hard your shoe can grip the floor 10) It is important because it means you can put more force on the ground with out slipping plus it helps you keep your footing. 11) Here we are at the 2010 Bowling US Open, Norm Duke is ready to throw his next shot, In order for the ball to hook it must slow down meaning that there is friction involved. There must be a high enough coefficient of friction between the ball and the lane in order for it to have the correct entry angle and to strike. Here is his beautiful release and he absolutely CRUSHES THE POCKET!!!!!!!

Physics Plus 1c. Wx=mg*sin(theta)= (1.5)(9.8)*sin30= 7.35 Wy=mg*cos(theta)= (1.5)(9.8)*cos30= 12.73 1d. µ= tan(theta)= tan30= .58

Bowling with Blocks Lab - Table One Difference ||
 * Tension(N) || Ff(N) || Total weight(N) || µ || Class Average µ || %
 * 1.9, 1.8, 1.9 || 1.9 || 7N || .27 || .325 || 16.9% ||

Table- Friction and Kinematics (g) || Mass (Kg) || Measured Time (s) || Measured Distance (m) || Ff (N) || Acceleration (m/s^2) || Calculated Vi (m/s) || Calculated Time (s) || % Error || Sample Calculations
 * Mass
 * 200 || .2 || 2.17s || 7.93m || .53 || -2.7 || 6.5 || 1.9s || 14.2% ||
 * 200 || .2 || 2.59s || 6.24m || .53 || -2.7 || 5.8 || 2.1s || 23.3% ||
 * 200 || .2 || 2.66s || 6.44m || .53 || -2.7 || 5.9 || 2.1s || 20.9% ||

- Ff^2=Vi^2+2ad for all 3 trials in order to find Vi - Vf=Vi+at in order to find time for all 3 trials

Part 3 1. Coefficient of friction is the amount of force it takes in order to move the object at a constant speed across a level surface. 2. Our value for µ was lower than every one else, theoretically the value should be the same but there is random and human error that is involved in the values. 3. My times were close for the most part and my percent error was a little higher than it should of been but there are several factors that contributed for those numbers. 4. The theoretical physics we are doing in class apply to the real world because detectives use these kind of problems in order to solve things like car crashes. 5. Three sources of experimental error are dust which would change the coefficient of friction, gaps in the floor that would change the slide of the block, the block turning sideways meaning that the distance it traveled would be shorter than actual, or the person may have not thrown the block at the 0m mark meaning that the measured distance would be messed up.

What do you think now? Some sports require different shoes because they might need more traction meaning a greater coefficient of friction or less traction meaning a lesser coefficient of friction. They would be useful because some features such as tiny spikes would increase friction giving the player better traction and better footing. In tennis sometimes a shoe with a lesser coefficient of friction is needed in order to slide toward the ball to get to it faster.

= Section 8 =

What Do You See/What do you think - The boy is trying to pole vault to the top of the party, The pole is converting horizontal motion into vertical motion - This difference between the pole and the the bar must be no more than .5 meters because if it were 1 full meter then they would not be able to clear the bar. Some variables that limit the height of a pole-vault is there, size, velocity, weight, and acceleration.

Investigate X8

Physics Talk - When an object gets acted upon by a force, it will change both its position and speed. It will come back to it's original speed and position. - There are three types of energy. Kinetic energy occurs when an object is moving (KE = 1/2 mv^2). Potential energy is the energy that an object has because of location (GPE = mgh). Elastic potential energy is the energy of a spring like object ready to spring (EPE = 1/2 kx^2). - Work is the product of the displacement and the force in the direction of the displacement. - The law of conservation of energy states that matter (energy) can neither be created nor destroyed. - All energy units are in Joules (J) **.**

Checking Up 1. A force is required to change the energy 2. From the ruler returning to its origional positon 3. he got it from the running start 4. Joules are used for all energy problems

<span style="color: #0000ff; font-family: Arial,Helvetica,sans-serif;">**Law Of Conservation Of Energy- total energy of a system remains constant while the types of energy change. Energy can be transferred. Only way to increase or decrease energy is to do work**

Physics To go 1. W-KE-GEP-KE-W 2. W-KE-GEP-KE-W 3. 1/2(m)(V^2)=9.8h h= 58.8m 4. The height the pole vaulter can reach is based on a few factors, their mass, veocity, length of the pole, and the flexibility of the pole 5. since some of the energy is lost from the running start, it goes away as the form of heat 6. KE=Wout 1/2mv^2=mgh 1/2(v)^2=44.59 v^2=89.18 v=9.4m/s 7. KE=W 1/2mv^2=Fd 1/2v^2=60.2 v^2=120.4 v=11m/s 8. GPE=KE mgh=1/2mv^2 1960=v^2 v=44.3m/s b) Yes because the masses cancel out 9. W=EPE  W=1/2kx^2  W=1/2(1500)(2.5)^2  W=46.9J  b) EPE=KE 1/2kx^2=1/2mv^2 V=30.6m/s 10. W=EPE Fd=1/2kx^2 f(30)=1/2(315)(30)^2 4725J=F b) 4725J 11. GEP=EPE  mgh-1/2kx^2  (.04)(9.8)(1)=9x^2  x=.21  12. F=ma  N=kg(m/s^2)(m)  W=Fd  J=Nm  GPE=mgh  =kg(m/s^2)(m)  =N(m)  = J  b) KE= 1/2mv^2 = kg(m/s^2)(m) = N(m) =J c) EPE=1/2kx^2 = N/m (m^2)  = N(m)  = J  13. EPE from the board transfers into GPE of the diver then into KE on the way down  14. W of a volley ball player to KE of the ball on the way up then to GPE at its maximum height and back to KE on the way down  16. When trying to pole vault the KE that someone has from the running start is all converted into an upward force so you can get launched up

What do you think now It is the speed of the pole that matters because the more velocity you have the greater force that is transferred into Potential Energy meaning you will go higher. The greater the energy the more energy that is conserved.

=Section 9=

What do you see/think- In the picture someone is jumping while spinning next to a helicopter - What do you think- no one can escape gravity but people can get out of it by exerting a force to counteract gravity.

Investigate X9 Pre-lab activity 2- The Skater was in the air for 20 frames 3. 20 frames*1/30= The skater was in the air for 2/3 of a second 4. At one point he is hanging in one general spot for a good 6 frames, it was frames 5-6-7-8-9- and 10. 5- The player is in the air for a total of 31 frames, he was in the air for about 1 second, because his launch angle was more vertical there was not defying of gravity.

1. What is the sequence of events in the jump? What types of energy are present at each stage?- bend your knees then exert a force into the ground and when in the air do not bend feet or knees.

2. What would you need to know in order oto measure the force needed to jump to a certain height? Design an experiment to measure the force of your push off the ground
 * What will you be able to conclude as a result of your experiment?- The force it takes to jump to a certain height
 * What data will you record?- height of the jump, Normal Force
 * What tools will you use to make your measurements?- Data Studio, scale, meter stick
 * How will you analyze your data? Data studio in the form of a line graph
 * Discuss your design with the teacher. Get approval before continuing.- 4

3. After getting permission, run your trials. - Height= .31m, Mass =111.1kg, GPE= 337.5J, F*d=Mgh = F(.18)=337.5= 1875J

4. When you have calculated the force, bring your work up to your teacher. Have the jumper, use the force platform and measure the actual force. - 2394.87J to jump, 21%error 5. How did your calculation compare to the measurement? - The calculations i got were not as high as the actual measurement of the forces

PTG 1. 50(9.8)(1)= 490 2. Work-GPE-KE-Work 4. if people want to prove or disprove something then they will have to back it up with statistical data or calculations showing why it is wrong. 5. F*d=mgh, so A increase in force or a decrease in mass 6a. 1*1=1J b. 1*10= 10J c. 10*1= 10J d. .1*100= 10J e. 100*.1= 10J 7. It would be the same amount 8. It would be the same amount 9. F*d=50*43= 2150J 10. 11. F=ma, 30/5= 6m/s^2 12. d=W/F 13. W=KE= 1/2mv^2 14. F*D=1/2mv^2 15.
 * || KE || GPE || EPE || SUM ||
 * || 1000 || 0 || 0 || 1000 ||
 * || 250 || 0 || 750 || 1000 ||
 * || 0 || 1000 || 0 || 1000 ||
 * || 850 || 150 || 0 || 1000 ||
 * || 0 || 50 || 0 || 0 ||


 * 16. || KE || GPE || EPE || SUM ||
 * || 0 || 1000 || 0 || 1000J ||
 * || 800 || 200 || 0 || 1000 ||
 * || 0 || 0 || 1000 || 1000 ||


 * 17. || KE || GPE || EPE || SUM ||
 * || 0 || 1000 || 0 || 1000 ||
 * || 250 || 750 || 0 || 1000 ||
 * || 1000 || 0 || 0 || 1000 ||

What Do You Think Now A Figure Skater does not defy gravity but since he uses a downward force to create a upward motion it only looks like he is defying gravity, the downward force is transferred into Kinetic Energy and then into Gravitational Potential Energy

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