FASHION AND PHYSICS!

1) Newtons first law. Newtons first law states that objects in motion will stay in motion, and objects at rest will stay at rest, unless acted upon by an outside force. 

Therefore, despite these crazy shoes, these models will not stop walking unless somebody pushes them over, they trip, or they decide to go the other direction; all examples of outside forces. 

2) Newtons second law. Newtons second law states that mass is inversely proportional to acceleration. Therefore, objects with less mass, can go faster than objects with more mass. In fashion, stick skinny models often walk the runway. While this ideal is kind of unrealistic, and the reasoning behind it may not be physics, the models with less mass can certainly walk the runway faster. 

Because this model has a very low mass, she can most likely move faster. 

3) Newtons 3rd law. Newtons third law states that for every action, there is an opposite and equal reaction. Because of this, if two runway models walked directly into each other, they would be exerting an equal amount of force during their collision. However, this does not mean that they have to have equal masses or accelerations. Rather, just the sum of their mass and acceleration must equal. 

 f=ma. 

f=Ma

f=mA

These two models exerted the same amount of force on each other when they collided. We know this because of newtons third law.

4) Washing Clothes. When we wash the clothes that we buy, many physics concepts can be applied. Clothes are trying to go straight (inertia) while the machine is going in a circle, causing the clothes to smack the sides therefore water is getting smacked out of them through the holes. Centripetal force acts on the clothes and they are forced in a circular path, but the water is not. 

5) Balance. When walking the runway, it is very easy for models to fall over, because it is very easy for them to lose their balance. This is because with their legs very close together, and their tall height when they walk, their center of gravity can easily fall out of the perimeters of their base of support. 

6) Backpacks. Why do we always have to bend over when we wear backpacks? This, like number 5, also relates to balance. By adding a backpack, you are adding more mass to yourself. Subsequently, your center of mass shifts. In order to stay balanced, and keep your center of gravity above your base of support, you have to lean forward. 

7) Why do pants need to be made so your legs can bend? Obviously, for us to walk. However, why do we have to bend our legs in oder to go fast? 

When you bend your legs, you are bringing your mass closer to your axis of rotation, therefore making it easier to spin, and go faster. 

8) Kinetic and Potential energy. Before a model walks (and is standing still) she has potential energy. However, when she starts moving, it is transformed into kinetic energy. When she stops again, it is back to potential energy. Potential and kinetic energy are central concepts that we learned in physics this year, as kinetic energy is basically the energy something has when it is moving. 

9) Work. Work is present when both the distance and force are parallel. In the chanel fashion show, they used a grocery store theme. As the grocery cart was pushed down aisle, both force and distance are parallel. Therefore, work is done. 

10) friction. Shoes are often made so that they can conduct a lot of friction with the ground. This is done so that people do not fall, and can formulate effective traction with the ground. 

Additionally, magnets! magnetic earrings? Magnetic nail polish? Physics relates to everything!

Wind Turbine Blog

Background: 

Wind turbines are used to convert energy from the wind into mechanical energy, and then into electrical energy. The wind turns the repellers which creates mechanical energy. This becomes the input for a generator. This process is exemplified through rotating the magnets around the coils of wire. This process causes a change in the magnetic field. This induces a voltage in the wire which creates electrical current. 

Materials:

-PVC pipes

-cardboard 

-coil of wire

-3 small round wooden pieces

-wooden rods

-magnets

-wooden box cutout.

Uses:

The PVC pipes were used as the body of our turbine, and also as the base of our turbine. Additionally, we used smaller pipes to put the actual generator inside. We made the repellers out of cardboard, and hot glued them to the rest of our turbine, to allow them to spin correctly. Inside the PVC pipe, we kept the generator. This generator was made with 2 small round wooden pieces. Glued to these, were 4 magnets. The north side of two of the magnets was facing out, while the south side of the other two was facing out. This allowed the generator to function. We attached this to a long narrow wooden pole, and stuck it out one of the sides of the PVC pipe through drilling a hole. This was difficult, because we had to use a wooden box cutout to make a small circle, so that the wooden rod would not move around too much. We got coils of wire and hot glued them to the sides of the PVC pipe to induce voltage. We used a small wooden circle to attach the the outside of the wooden rod, so we could glue the repellers onto it, and our turbine could function. 

Results/discussion:

Well, despite the efforts from the Wyatt, Carson, Will trio, our results were slightly on the side of disastrous. Unfortunately, we only generated .1 volts of power, and did not have time to improve this. However, this was caused because of our repellers. They were very weak, had hardly no support, and barely even moved. Everything else on our turbine was perfectly functioning. This was our first and last try therefore the repellers are the only thing that I can advise working on. 

Unit Blog Reflection

MAGNETISM 

In this section, we learned about magnetism. This includes many interesting aspects for example what causes the northern lights, how credit card machines work, and many other topics. 

Basics of Magnets.

Moving charges are the source of all magnetism. All magnets have a north and south pole, and the field lines run north to south inside, and outside, south to north. If you cut a magnet in half, it too will form a north and south pole. The earth also has a geographical north and south pole along with a magnetic field with a north and south pole. Domains are clusters of electrons moving in different directions. When domains are aligned, they form north and south poles. Like poles of a magnet repel, and opposite poles attract. 

Compasses

The compass is a little magnet that can spin freely. The north end of the magnet attracts to the south end of the earth, while the south end of the magnet, attracts to the north end of the earth. This attraction causes the needle to align with the earth's magnetic fields. The north pole of the compass points to the correct geographic north because the earth's geographical poles differ from the earths magnetic poles.

How Can a paper clip become a magnet?

Originally, the paper clip is not magnetized. The domains within the paperclip are all moving in random directions. However, when a magnet is held up to the paper clip, the domains align, forming north and south poles. These north and south poles are attracted to other north and south poles, thus becoming a magnet. 

Cosmic Rays

Cosmic rays enter the earth through the poles rather than the equator. This is because the force felt through the magnetic field of the earth, causes the rays to spiral around the equator into the poles. The poles run parallel to the rays, where as the equator runs perpendicular. The northern lights are caused by these cosmic rays entering. 

Electromagnetic Induction

Out of everything that we have studied in this unit, I think that I struggle most with electromagnetic induction. Induction being a concept I had to wrestle a lot with last unit, it was difficult to see it again in an even more complex way. Electromagnetic induction is a way to increase voltage by changing the magnetic field in loops of wire. The change between a magnetic field and loops of wire, is what induces voltage. The more loops in a magnetic field, the more voltage, subsequently, the more resistance. When the magnet is inserted through or around the loops, there is a change in the magnetic field of the loops. The induced voltage also makes a current. The change in magnetic field also induces the current. The amount of current produced in electromagnetic induction depends on induced voltage, the resistance of the coil and the circuit, and the change in current in a nearby loop. 

ApplicationIn the pavement, there is a loop of wire. When the car, which is magnetic, moves over the wire, it changes the magnetic field of the loop. This change in the magnetic field induces voltage, which causes a current. This current is a signal to the stoplight to change. Metal detectors and credit card machines undergo a similar process.

Generators

If you continuously change the magnetic field, that is how a generator works. Through electromagnetic induction, generators turn mechanical energy into electrical energy. (Mechanical energy is a magnet that moves, whereas electrical energy is current in a wire. 

Generators use resources such as wind or water to turn loops of wire inside of a magnet. It relies on the change in the magnetic field rather than the force of the magnetic field. This change in the magnetic field induces voltage which causes current, which is the current we tend to use in our households

Motors

Motors are similar to generators, but Motors transform electrical energy into mechanical energy.  Moving charged particles feel a force when moving perpendicular to a magnetic field. The force felt by the wire causes a torque. Motors work from the force of the magnetic field. Motors can be used for things like cars. Basically, a current runs through a coil, which feels a force because it is within a magnetic field (moving charges feel a force in a magnetic field). This causes the coil to spin, producing usable mechanical energy. 

Transformers

A transformer is a device used for increasing or decreasing voltage or transferring electric power from one coil of wire to another through electromagnetic induction. A transformer is made up of two coils of wire. One wire is a primary coil, and the other is a secondary. The primary is is directly connected to the power source. Therefore, the primary is the input, the secondary is the output. Whenever the primary switch is open or closed, voltage is induced into the secondary current. AC current runs through the primary, which causes a change in magnetic field. DC cannot be used, because the current it produces only goes in one direction. The more turns in the wire, the more voltage is produced. If the secondary has more turns the primary it will produce more voltage than the primary and the voltage will said to be stepped up. If the secondary has less turns than the primary it will produce less voltage than the primary and the voltage will said to be stepped down.

FORMULAS

power in = power out

primary power/primary turns=secondary power/secondary turns

power=voltage x current

IV=IV

Vi=vI

ENERGY ALWAYS REMAINS CONSTANT

To conclude...
The area that I struggled most in, was electromagnetic induction. As I mentioned before, I had trouble with the concept last unit, and as it occurred in this unit also, it became even more complicated. I overcame this by looking at different people's blogs and talking to Mr. Rue for extra help. Additionally, I had issues with transformers, but I got over this by also looking at blogs and seeking extra help. 

Motor Blog

Here is a picture of a typical battery powered motor. To make our motor, Will, Wyatt, and I used a piece of wood, a battery, magnets, paper clips, tape, a rubber band, and a coil of wire. We began by attaching the battery to the piece of wood with tape. We then formed hooks with paper clips, and attached them to the ends of the battery. We made the wire into a small loop with two tails in order to allow it to hang between the paper clips. We then placed the magnets on the battery.

reason for battery: supplies voltage and current
reason for coiled wire: provides a pathway for current to flow. Coil=thicker wire/ more wire= more possibility for current to flow, more power. 
reason for paper clips: connects wire to battery, completes the circuit
reason for magnet: attraction makes the loop of coil turn creating a magnetic field

Armature 
In order to allow our motor to function correctly, we had to scrape off one side of the coil. This let current flow throughout the circuit. We only scraped off one side because if we scraped all around, current would want to flow in both directions. We then attached the wire to the paper clip to allow the flow of current. 

Why does the motor turn? 
The magnetic field is the reason the motor is able to function. The force of the magnet is charged by the battery which is perpendicular to the motor. This creates force. The magnet causes a magnetic field, therefore charges move in one direction, causing the motor to rotate. It is able to turn because the force is in one direction. Again, we scraped off the sides of one end of the coil, because if force was going in both directions, the motor would not be able to function. 

Unit Blog Reflection

ELECTRICITY!

Units
Charge - q (Coulomb)
Voltage - V or J/c (volt or joules per charge)
Current (I) - A
Power - W (watts)
Resistance - Ω (ohm)

In electricity, there has to be a complete circuit. There must be a negative and positive end.

Electric Fences

When you touch an electric fence, the shock goes through your body, into the ground, and then back up to the fence, in a circuit. 

However, when you stand on a tile, the shock cannot get through you into the ground, therefore, you cannot get shocked, because it cannot go in a circuit. 

How does energy go through a wire?

when light switch is turned on, energy is pushed forward and wires are connected, the charges are pushed into the bulb...light! When it is turned off, the wires are disconnected.

CURRENT ALWAYS FLOWS THROUGH THE PATH OF LEAST RESISTANCE

CHARGES

positive charges=protons

negative charges=electrons

neutral charge=when protons and electrons are even

like charges repel each other

opposite charges attract eachother

Polarization
conductors vs. insulators
Conductors: charges can move through them, can become polarized
Insulators: stops charges from moving
*polarization*--Is when charges in an object completely separate. charges move to opposite sides and the object as a whole becomes neutral. 
(he wears polarized ray ban sunglasses.) 
Colomb's Law
The force between 2 charges is inversely proportional to distance. 
F=K(q1q2/d^2)

Big question....polarization question!
Why does a charged piece of cling wrap attract to a ceramic bowl?
when the charged cling wrap gets close to the bowl, the bowl polarizes. Positive charges go towards the cling wrap and negative charges repel away from it. The bowl is polarized therefore has a neutral charge. Since the distance between the opposite attractive charges is less than the distance between the repelling charges, the attractive force is greater than the repelling force. (Colomb's law)-F=K(q1q2/d^2) So....because the attractive force is greater, the cling wrap is attracted to the ceramic bowl.

Big question....(sorry I know its scary, but this is the best picture I could find)

Why does your hair stand up after you put on a sweater?

Sweater rubs against hair and steals electrons through friction. Sweater becomes negatively charged and hair becomes positively charged. So hair sticks up because it is attracted to the negative sweater as you put it over your head. Additionally, it repels itself because it is all positively charged. 

3 major ways to charge something

1) Contact: transfers charges

2) Friction: when something rubs up they can steal electrons

3) Induction: charge without contact

Induction in more detail:

Induction is caused by putting a positive object next to something without actually touching it. It is all about electrical force, force between different charges. 

Electrostatics: Charges that are not moving

Circuits: not a part of electrostatics

Lighting 

How does lightning work?

Clouds are charged by energy from air currents. This causes the bottom of clouds to become negatively charged. These negative charges create a charge separation in the earth. (positive is attracted upward, negative repelled downward). The negative charges in the cloud bottoms and the positive charges in the ground build up, eventually the charges equalize across the air, releasing energy in the form of light heat and sound....Lightning! 

Lightning rods?

Lightning rods protect buildings from lightning...but how? First, they collect positive charges from the ground and the travel up then stand above the building in the open air. Lightning will take the path of least resistance. The lightning rod will provide far less resistance than the house. Therefore, the lightning will hit the lightning rod rather than the house; thus, protecting the house. 

ELECTRIC FIELDS AND SHIELDING 

Electric field: an area around a charge that can influence (push or pull) another charge

for positive charges, arrows face outward. For negative charges, arrows face inward.

**if the arrows are closer together, that means the electrical field is stronger**

ELECTRIC SHIELDING

Why do we keep electronics in metal boxes?

The metals charges are all evenly distributed. Therefore, while positive charges accumulate around the box, the objects inside will not feel anything at all. The metal stops them from doing so, and they will not feel a force. 

VOLTAGE

voltage=charge difference, the difference in potential energy between two points

bigger charge=bigger voltage=bigger force=higher energy

V=change in PE/q

CURRENT

Current=the flow of charge

VOLTAGE CAUSES CURRENT

2 types of current

AC=alternating current

-switches directions

-used in batteries 

DC=direct current

-does not switch directions

-used in wall sockets

How do batteries work?

Batteries have a voltage (or electrical potential difference), therefore have a current. This is because there is a negative a positive side of a battery. This allows a battery to function. However, overtime the difference decreases which means there is no voltage which means no current, so it stops working.

Why do flashlights get dimmer?

This is practically the same question. As the battery gets weaker over time, the voltage therefore current decreases. This means less charge flowing through the bulb and less energy getting transformed into light. So....the light gets dimmer.

ELECTRIC POTENTIAL

charged objects have electric potentials through their location in an electric field.

EP=PE/q

gaining electric potential does not mean gaining kinetic energy

Flashing lights

Cameras use capacitators to use their flash. Capacitators build up energy over a period of time and release all at once. Because of this, photographers cannot back to back take flash photography because the flash needs time to rebuild energy. 

**quick side note. Electrons are NOT as fast as light, in conductors they are relatively slow. they move in a pack like formation**

OHM'S LAW

Current depends on voltage and electrical resistance.

V= I x R

Resistance

Resistance is effected by a couple aspects of a wire

-Thicker wire=more resistance

-Longer wire=more resistance 

-Heat=more resistance

Why do lightbulbs sometimes blow when you first turn them on?

When a lightbulb is turned off, the filament is cooled, which means very little resistance. When it is turned on, a lot of currents is rushed into the lightbulb without much resistance causing it to sometimes blow. 

ELECTRIC POWER

EP=energy/time

EP=V x I

SERIES AND PARALLEL CIRCUITS

circuit=the path in which electrons can flow

Series circuit

-voltage adds

-current decreases

-resistance adds

-one light bulb out, all light bulbs out...this happens when the fuse melts when the current reaches a point that is too great the fuse melts therefore cutting the circuit so everything goes out because they are no longer attached to voltage source.

Parallel circuit 

-voltage stays the same

-current adds

-brightness stays the same

-resistance decreases by half

I thought that this video was really helpful in understanding this concept. I like how they used colorful writing and wrote/drew as they explained the concept.

Voltage Recourse

Out of all of the videos that I looked at, I found this video most helpful. I think that they did a great job verbally describing voltage while also drawing it out as they talked. This kept me engaged as I was both hearing and seeing the information. I recommend this to anyone who does not understand voltage.

MOUSETRAP CAR

CARSON AND JASMIN'S MOUSETRAP CAR!

Speed: 8 seconds
Place (in class): 7th 

So how did we design our car? 

 (labeled picture from Jasmin's blog)

This picture basically shows the general design of our car. 

Wood base: We used the wood as a base of our entire car. We originally used cardboard, however, we realized later on that the cardboard was not strong enough to support the mousetrap, and the many other things we attached to it. Unlike the cardboard, the wood did not bend. Therefore, it was much stronger. Through having a strong base, the car was more balanced and steady. 

Metal rod (lever arm): For the lever arm, we used a thin metal rod. Similarly to the wooden base, we realized that we needed to use a material that would not easily bend or break because of the force that would be exerted on it. The metal rod was extremely strong therefore could handle the force of the mousetrap. The purpose of having the lever arm was to hold back the string so we could wind it up. When we let go of the lever arm, it would slowly move forward as it allowed the string to unwind, moving the car. We used duck tape to attach the lever arm to the mousetrap.

Wiry string: We used string to attach the lever arm to the front of the car, allowing it to move. We originally used a thick string, however realized that it got caught in the front of our car because of its size. Instead, we found a very thin string in the art room that took up much less space. The string was wound up and allowed the lever arm to unwind it when we let go, allowing the car to move. We duck taped the string to the lever arm, and hot glued it to the axil. 

Mousetrap (obviously): The mouse trap was the power house of our car. Through the force exerted when we set it off, the car moved.

Wheels/axils: Luckily, we were able to pull the wheels (and the metal rods they were attached to) straight off my brother's old playmobile car. (although it did take a good hour of smashing the car with a hammer to do so.) These wheels were great given the fact that they were designed to move a small car. The rubber tire material created traction. Also, they were very evenly balanced which allowed the car to move in a straight direction. We hot glued the front wheels to the wooden base, however, we were not able to do that on the back wheels because we needed the axil to spin at the same rate as the wheels. Because of this, we had to hot glue the wheels to the axil and then use binder clips to attach the axil to the rest of the car. 

Broken Chopsticks: The chopsticks were used as something for the binder clips to grip onto. The clips would not clip onto the wooden base, so we hot glued chopsticks so that they could attach. 

Binder Clips: The binder clips were just big enough to attach the wheels to the wooden base while still giving them room to spin. We put the axil in the wholes of the binder clips, then clipped them onto the car. This was effective as we were able to also move the clips forward or backward to stop the car from turning in a certain direction. 

Heres a video of our car

Our car does go pretty slow, however it goes over 5 meters! 

REFLECTION

Newton's Law's application in our car

Newtons 1st law: Newtons first law states that objects in motion will stay in motion unless acted upon by an outside force. This was applied in our mouse trap car, because through setting off the mouse trap, our act acted as an outside force. Therefore, it started moving. Additionally, when our car would run into a wall, or friction increased, that would act as an outside force as well, causing the car to no longer be in motion.

Newtons 2nd law: Acceleration is produced when force acts on mass. This was present in our car because the force of us setting off the mousetrap acted on the mass of the car. Because this law states that mass and force are inversely proportional to acceleration, we tried really hard to keep the car as light as we could so that it would go faster. 

Newtons 3rd law: Newton's 3rd law states that for every action, there is opposite or equal reaction. This meant that with whatever action our car produced, the ground would do the same. Therefore, the balance and strength of our car became a very important factor in building it. This is why we have the strong metal lever arm, wooden base, and balanced wheels. We tried to keep everything evenly distributed, (binder clips etc). We wanted the mass to be even on both sides of our car. 

FRICTION?

The two types of friction that were present in our mousetrap car were static and kinetic. I think that the problems we encountered most when dealing with friction was wheels. Before we found the playmobile car, we had ideas of using cd's or records. However, because of the very thin edges of both of these objects, not much friction would be produced. So, instead of using them, we found the other wheels which were chiseled and rubber, therefore created a lot of friction. Through having a lot of friction, the tires were able to grab the ground more effectively, and move forward. Through doing this, we used friction to our advantage. 

WHEELS? 

Jasmin and I originally wanted to use three wheels. We wanted to use two records in the back, and a CD in the front. However, as we researched more, we not only realized that this would not create enough friction, but it would not be as balanced. Through using 4 wheels of equal sizes, our car was very balanced, reducing it's want to turn to certain sides or tip over. Although three wheels could have been effective, we decided that balance was more important. Our wheels were not too big not too small. The benefits of having larger wheels is that through each rotation, the wheels will cover more distance. However, they are also heavier than smaller wheels. While smaller wheels are lighter, they cover much less distance in each rotation. So, we decided to do a medium size for a compromise between them both. 

CONSERVATION OF ENERGY

The law of conservation of energy states that energy can neither be created nor destroyed, but can only change form. Both kinetic and potential energy were very present in our car. However, the amount of energy in my car remained the same throughout the entire project. Therefore, our focus became how efficiently we could use this energy. By pulling back the lever arm that was attached to the string, we tried to store the maximum amount of potential energy so that when we let go, it could transform into as much kinetic energy as possible. 

LEVER ARM

The lever arm was not a difficult aspect for us. Moe gave us the rest of his metal rod (which was a lot) so we just used that. We realized that the longer the lever arm, the farther the car will go. This is because we could use more string and have the car go for a longer amount of time as the string is what allowed the force of the mousetrap to move the car. Because of this, we wanted to make it pretty long. We also wanted the lever arm to be directly attached to the mousetrap so that the force will remain strong. So, we securely duck taped it to the mouse trap. We also made sure that the metal rod was strong as we did not want it to bend under the force of the mousetrap. Because it was strong and sturdy, it was able to store as much potential energy as possible. I think that the only negative part of this is because it was so long/heavy it did reduce the speed of the car. We focused a lot on distance when we should have been a little bit more speed prioritized. 

ROTATIONAL AND TANGENTIAL THINGS

We definitely took tangential velocity into consideration as we designed the wheels. Tangential velocity is the speed an object moves in a circular path. The distance from the axis of rotation is a major factor of this. So, bigger wheels would mean more tangential speed. We avoided using really small wheels for this reason. However, as I mentioned earlier we also wanted our car to be balanced so we didn't use too big of wheels. Rotational velocity is how fast the wheels spin. By having really big wheels, that means the mass would be further away from the axis of rotation therefore have less rotational velocity (and more rotational inertia!!) and go slower. So, we needed to find a compromise between having a lot of rotational velocity or tangential velocity. We did this by having medium sized wheels which benefited from both tangential and rotational velocity. Additionally, rotational inertia was applied in our car as it is the property of an object to resist change of spin. Through having the mass of the wheels further away from the axis of rotation we had more rotational inertia. Again, we needed to find a compromise of medium wheels in order to find a good balance of all three of these properties. 

CALCULATIONS??

WE CANNOT CALCULATE WORK BECAUSE THE FORCE AND DISTANCE ARE NOT PARALLEL! While the force is vertical, the distance is horizontal, which means NO WORK IS DONE. Potential energy is Pe=mgh. However, we cannot calculate the potential energy because we do not know the height or mass of the system. Because we do not know the potential energy, we also cannot figure out the kinetic energy because we do not know the velocity or mass. Additionally, we cannot know the acceleration because we do not know the speed our car traveled. In order to find the force in the acceleration problem we would have to solve for the f variable. This would mean that we would have to know the total acceleration which as I mentioned earlier, we do not. 

Reflection
Our final design completely differed from our original design, We originally wanted to have three wheels, using CD's and records. Additionally, we had no plans for a lever arm. However, as we researched more and tried out different things, we realized the changes that we needed to make. I don't think anything in particular really prompted our changes. We just tried everything out, and when it didn't work, we changed it. We also got a lot of inspiration from other people's cars. We would watch what did and didn't work for them, and take it into consideration as we tried certain things. 
We definitely encountered a lot of problems in this project. I think the first major issue we had is figuring out where to start. We spent an entire class period honestly doing nothing because we could not decide what to do. This was pretty difficult as we fell behind everyone else. However, I began spending more time at home planning ideas, while Jasmin would as also. We also had issues with the axil. We had no idea how to securely attach the axil to the car while also allowing it room to rotate. However, with the help of Mr. Rue, Jasmin suggested binder clips which was a great idea. Then, we used the leftovers of broken chopsticks to execute this idea. Although the binder clips left room for string, it was not much. This became a problem as the string we originally used became tied up in the binder clips when we would let go of the lever arm. We fixed this by finding thinner string. Finally, our last issue was our car would constantly curve to the left, running completely into the wall. Luckily, we were able to easily move the right binder clip up, which slightly curved the wheels to the right, making the car go in a straight path.
If I was to do this project again, I think I would definitely work on finding lighter materials. While our materials were very steady and strong, I think in some cases they were heavy, which prevented our car from going really fast. This was particularly present in our lever arm. It was a lot longer then it needed to be and while it was effective in distance, it slowed down our car. Overall however, I am really proud of the work Jasmin and I put into this project, and despite our 8 second time, I'm really happy that we made it 5 meters and the success we had with this car. 

Unit Blog Reflection

UNIT BLOG REFLECTION

In this unit, I learned.....

WORK AND POWER

when a force moves something through a distance, work is done. 

Work= force x distance 

Work is measured in joules. 

When is work present?

Work is present when both the force and distance are parallel. When grocery shopping, both your distance and force are parallel when pushing a cart, therefore work is being done. 

Also, when this boy pushes a sled, work is being done because force and distance are parallel. 

WHERE IT GETS TRICKY

Stairs....

Stairs can be confusing. If you are going up stairs you DO have work, however, the confusing aspect is what distance you use, as there is a horizontal and vertical distance. YOU USE THE VERTICAL DISTANCE. 

Let's try this out

I need to go to second mitchell. In which case will I use more work, the stairs or the elevator?

Answer: I will use the same amount of work in both cases because I will have the same force as well as travel the same distance. 

Is work present in this? ^^^

Answer: No, there is no work because the force and distance are not parallel. While the distance is horizontal, the force is vertical. Also, there is no work on the tray because it is moving. 

Also, if someone is pushing something and it does not move, no work is done. 

POWER

power is how quickly work is done. 

power=work/time

power is measured in watts

1 Horsepower=746 watts

Light bulbs

So, 100watt light bulb will generate more power therefore do work faster than a 60 watt lightbulb. 

WORK AND KINETIC ENERGY RELATIONS
Where did work come from?
Mass & speed have the ability to do work
movement fuels energy
SO....
Kinetic Energy=1/2mv^2

change in kinetic energy=KE(final)-KE(initial) 

kinetic energy is basically energy something has when moving

This polar bear is generating kinetic energy because it has a velocity and mass, and as it moves, this is being applied into kinetic energy. 

does he have kinetic energy?

he does not have kinetic energy because he does not have a velocity. If something does not have a velocity, it cannot have kinetic energy. 

CONSERVATION OF ENERGY
key question:

Why do airbags keep us safe?

1) When we are riding in a car, we are moving, therefore doing work.
2) kinetic energy=1/2mv^2
3) change in kinetic energy=KEfinal-KEinitial 
4) change in kinetic energy=work
5) work=force x distance
6) the airbags increase the distance therefore the force is less. conservation of energy: work with airbag=work with dash

POTENTIAL ENERGY
Potential energy=potential energy is the energy of position. Movement can be transformed into kinetic energy. 

when you throw something up, because of the force of gravity, the higher you get up, the less kinetic energy you will have as it will be converted to potential energy

when kinetic energy goes up potential energy goes down and vice versa

PE=mgh
so how do roller coasters work?

roller coasters are able to function because they store up potential energy then it is converted into kinetic and then back to potential, then back to kinetic, and so on. The law of conservation of energy.

INCLINED PLANES/MACHINES

we use ramps to ultimately reduce the amount of force it takes to get somewhere, when you increase the distance, the force is less. That is what ramps do. 


machines also reduce the amount of force and increase distance


For pulleys, tension on each side is equal. 

SCISSORS

the long handle and short blade allow scissors to cut with more force

EFFICIENCY=workout/workin

the work out can never be more than the work in

WHAT I FOUND MOST DIFFICULT
This unit was definitely difficult. I struggled in a lot of areas, particularly the machine section. However, I got over these difficulties through conference period and looking at other peoples blogs. The light bulb clicked when doing so. 

My problem solving skills got better....
Obviously, the more we solve problems, the better we will get at them. Therefore, the more problems I do, the better I will get at them. Through doing take home quizzes, I was able to really sit down and work things out slowly, therefore understand problems better. Through this process, I was able to improve my problem solving skills. 

My goals for next unit is to do better on quizzes, because I recently scored poorly on the latest quiz. In order to do this, I need to work harder to seek extra help when I need it. 

REAL LIFE? Real life connections are present throughout my explanations. 


MY PODCAST WILL NOT EMBED SO HERE IS A LINK!

http://www.youtube.com/watch?v=zEGO1eI-SNg