- Kinetic Energy is energy that is in motion. Moving water and wind are good examples of kinetic energy. Electricity is also kinetic energy because even though you can't see it happen, electricity involves electrons moving in conductors.
- Potential Energy is stored energy. Examples of potential energy are oil sitting in a barrel, or water in a lake in the mountains. This energy is referred to as potential energy, because if it were released, it would do a lot of work. Energy can change from one form to another. A good example is a Roller Coaster. When it is on its way up, it is using kinetic energy since the energy is in motion. When it reaches the top it has potential (or stored) energy. When it goes down the hill it is using kinetic energy again.
- Mechanical Energy is the energy of motion that does the work. An example of mechanical energy is the wind as it turns a windmill.
- Heat energy is energy that is pushed into motion by using heat. An example is a fire in your fireplace.
- Chemical Energy is energy caused by chemical reactions. A good example of chemical energy is food when it is cooked.
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- Electrical Energy is when electricity creates motion, light or heat. An example of electrical energy is the electric coils on your stove.
- Gravitational Energy is motion that is caused by gravity. An example of gravitational energy is water flowing down a waterfall.
- Nuclear Energy: Certain elements have potential nuclear energy, such that there are internal forces pent up on their nucleus. When that potential energy is released, the result is kinetic energy in the form of rapidly moving particles, heat and radiation.
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- Light is the movement of waves and/or light particles (photons). It is usually formed when atoms gain so much kinetic energy from being heated that they give off radiation. This is often from electrons jumping orbits and emitting moving photons.
- Sound Energy: Sound waves are compression waves associated with the potential and kinetic energy of air molecules. When an object moves quickly, for example the head of drum, it compresses the air nearby, giving that air potential energy. That air then expands, transforming the potential energy into kinetic energy (moving air). The moving air then pushes on and compresses other air, and so on down the chain. A nice way to think of sound waves is as "shimmering air".
Friday, December 10, 2010
Feeling.... energetic : D
ready the CANNONS... FIRE IN THE HOLEEE~!
Cannons first appeared way back in the 14th century in Europe. Through times people developed and advanced the design of cannons and today, cannons are still widely in use for military purposes. The thing that makes cannons so effective is that it is able to fire heavy explosive while giving it incredible speed. Referencing Newton's second law of F=ma, we know that Cannons fire with huge amount of force.
The image above is the M242 25mm caliber Bushmaster Auto cannon. It is developed and utilized by the U.S. military. This cannon is possibly the most advanced and destructive one in the world. It fires with incredible precision and it can cause severe destruction to the enemy.
To maximize the horizontal distance of the cannon ball, there is a couple factors that needs to considered. First, the angle of the cannon should be 45 degrees to the ground. This will enable more air time therefore more distance for the cannon ball. Secondly, the height of the starting point for the cannon ball needs to be as high as possible. This, too, will give the cannon ball more air time and more horizontal distance.
The image above is the M242 25mm caliber Bushmaster Auto cannon. It is developed and utilized by the U.S. military. This cannon is possibly the most advanced and destructive one in the world. It fires with incredible precision and it can cause severe destruction to the enemy.
To maximize the horizontal distance of the cannon ball, there is a couple factors that needs to considered. First, the angle of the cannon should be 45 degrees to the ground. This will enable more air time therefore more distance for the cannon ball. Secondly, the height of the starting point for the cannon ball needs to be as high as possible. This, too, will give the cannon ball more air time and more horizontal distance.
Thursday, December 9, 2010
The various problems of Mr. Newton
Equilibrium occurs when the object has no acceleration.
Assumptions:
- No friction
- a= 0
FBD of an Equilibium
In this type of equilibrium, all the forces cancel out each other therefore there is no acceleration present.
For this type of equilibrium questions, it can be solved using a method very similar to vector components.
Inclines:
There are two types of Incline questions, kinetic and friction.
Kinetic:
In most of the kinetic incline questions we've studied, the mass is either sliding down or moving up. This gives it an acceleration. There is no Y acceleration because the object is not moving up and down as it slides on the incline plane.
assumptions:
The important thing to remember for this type of questions is to break mg into its x and y component. Because we know that there is no Y acceleration, therefore FN=mgy. For X, there are a couple of things that we need to take into consideration of. There are friction, and force gx, sometimes force applied. Fxnet = Fgx-Ff
Friction:
For friction questions, the mass is staying still, which means that a = 0.
The trick to this question is that the acceleration equals to zero, which sort of resembles equilibrium except with friction. You would have to split the mg into its x and y component just like the kinetic problems. Fn - Fgy = 0, Ff-Fgx=0
Pulleys:
The kind of pulleys we have studied is fixed to a frame. The trick to remember for this question is that the tension between the two strings are the same. Therefore, if we find the equation for tension for both of the strings, we can set them equal to each other and find the missing variable.
Trains:
Bacially, it's pulleys, but sideways.
The yellow blocks are in a train system while the blue is in a pulley system.
The acceleration in a train system is always assumed to be the same between the masses.
Assumptions:
- No friction
- a= 0
FBD of an Equilibium
In this type of equilibrium, all the forces cancel out each other therefore there is no acceleration present.
For this type of equilibrium questions, it can be solved using a method very similar to vector components.
Inclines:
There are two types of Incline questions, kinetic and friction.
Kinetic:
In most of the kinetic incline questions we've studied, the mass is either sliding down or moving up. This gives it an acceleration. There is no Y acceleration because the object is not moving up and down as it slides on the incline plane.
assumptions:
Assumptions
- fk = µkFn
- aₓ ≠ 0, ay = 0
- +ve in the direction of a
- +ve in the direction of a
- no air resistance
The important thing to remember for this type of questions is to break mg into its x and y component. Because we know that there is no Y acceleration, therefore FN=mgy. For X, there are a couple of things that we need to take into consideration of. There are friction, and force gx, sometimes force applied. Fxnet = Fgx-Ff
Friction:
For friction questions, the mass is staying still, which means that a = 0.
Assumptions
- fs = µFn
- a = 0
- +ve axes in the direction of decline
- no air resistance
- no air resistance
The trick to this question is that the acceleration equals to zero, which sort of resembles equilibrium except with friction. You would have to split the mg into its x and y component just like the kinetic problems. Fn - Fgy = 0, Ff-Fgx=0
Pulleys:
Assumptions
- frictionless pulleys + rope
- no air resistance
- multiple FBDs
- +ve in the direction of a
- T1 = T2
- a of the system is the same
The kind of pulleys we have studied is fixed to a frame. The trick to remember for this question is that the tension between the two strings are the same. Therefore, if we find the equation for tension for both of the strings, we can set them equal to each other and find the missing variable.
Trains:
Bacially, it's pulleys, but sideways.
Assumptions
- fk = µkFn
- aₓ ≠ 0, ay = 0
- +ve in the direction of a
- +ve in the direction of a
- no air resistance
The yellow blocks are in a train system while the blue is in a pulley system.
The acceleration in a train system is always assumed to be the same between the masses.
Tuesday, November 9, 2010
My... unique experience with roller coasters
Personally, I am NOT a big fan of roller coasters because it brings back memories such as this one...
It was a hot day during the summery break and me and my friends decided to take a trip to Toronto and visit Canada's Wonderland.(i went to elementary school in Ottawa, so like coming to Wonderland was a big deal)
We got up early and arrived at about 1 in the afternoon. We were so excited as we went on 6-7 coasters in a roll.
Before we know it, it was almost 4 and we were starving because none of us had lunch. So we decided to get lunch. As i remembered clearly, i had bought a fries supreme from NY fries. It turned out to be one of the worst decision i've made.
After i chowed down my fries, i decided to go right back to coaster riding as i was determined to not miss even one moment of this awesome funess. Before i knew it, my butt was on the seat of "The Bat" then everything went wrong...
As the ride was lifting off, i felt great, i was still chatting and waiting anxiously for it to accelerate. BUT after the ride was accelerating faster plus the twist and turning, i began to have this funny feeling in my stomach. After about the 4th turn, my face was completely pale and my stomach felt so bad that i can barely breathe! But i was determined to make it out of this ride, without causing a whole mess... i held back the vomiting. Then the ride flip me side ways, backwards, even upside down. By that point, my fries that i ate early were literally at my throat... HOWEVER, with A LOT of efforts, i managed to keep my fries at my throat. Finally the ride came to an end and i can see the enter and exit platform. i felt so relived and just when i thought i was going to make it, the coaster made a rather rash stop. As i leaned forward and as the seat belt compressed my stomach, brownish fluids exploded out of my mouth and even my nose. The next thing i remembered, i was sitting a bench not far from the ride with an angry,balding, middle aged man glaring down at me and trying to wipe his neck at the same time. At the end of the day, i had a lot of fun and i was also glad there weren't any lawsuits.
From that day on, I've never went on "The Bat" and i have never eaten New York fries. So that's my unique experience with roller coasters.
It was a hot day during the summery break and me and my friends decided to take a trip to Toronto and visit Canada's Wonderland.(i went to elementary school in Ottawa, so like coming to Wonderland was a big deal)
We got up early and arrived at about 1 in the afternoon. We were so excited as we went on 6-7 coasters in a roll.
Before we know it, it was almost 4 and we were starving because none of us had lunch. So we decided to get lunch. As i remembered clearly, i had bought a fries supreme from NY fries. It turned out to be one of the worst decision i've made.
After i chowed down my fries, i decided to go right back to coaster riding as i was determined to not miss even one moment of this awesome funess. Before i knew it, my butt was on the seat of "The Bat" then everything went wrong...
As the ride was lifting off, i felt great, i was still chatting and waiting anxiously for it to accelerate. BUT after the ride was accelerating faster plus the twist and turning, i began to have this funny feeling in my stomach. After about the 4th turn, my face was completely pale and my stomach felt so bad that i can barely breathe! But i was determined to make it out of this ride, without causing a whole mess... i held back the vomiting. Then the ride flip me side ways, backwards, even upside down. By that point, my fries that i ate early were literally at my throat... HOWEVER, with A LOT of efforts, i managed to keep my fries at my throat. Finally the ride came to an end and i can see the enter and exit platform. i felt so relived and just when i thought i was going to make it, the coaster made a rather rash stop. As i leaned forward and as the seat belt compressed my stomach, brownish fluids exploded out of my mouth and even my nose. The next thing i remembered, i was sitting a bench not far from the ride with an angry,balding, middle aged man glaring down at me and trying to wipe his neck at the same time. At the end of the day, i had a lot of fun and i was also glad there weren't any lawsuits.
From that day on, I've never went on "The Bat" and i have never eaten New York fries. So that's my unique experience with roller coasters.
Physics behind rollercoasters
Generally, when people think of roller coasters, they think of a fun and exciting, vomit producing machine. But what many people don't realize is that there is also a wealth of Physics knowledge behind this functioning machine.
The first part of the roller coast normally involves work and energy. At the beginning of an average roller coaster ride, there will be mechanical forces such as a lift motor or a chain to help the roller coaster up a steep hill with little momentum. From there, gravity will take over.
On the top of the steep hill, the coaster processes a lot of potential energy. This potential energy is created by the mechanical forces which gave coaster the height and the weight of the coaster also contributes to the potential energy.
As the coaster moves down, potential energy turns into kinematic energies. The more the coaster accelerates the bigger values of kinematic energy is being presented and at the same time, the value of potential energy decreases and react inversely. As the ride continues, the train of cars are continuously losing and gaining height. Each gain in height corresponds to the loss of speed as kinetic energy is transformed into potential energy. Each loss in height corresponds to a gain of speed as potential energy is transformed into kinetic energy. AND that's how a roller coaster works.
The first part of the roller coast normally involves work and energy. At the beginning of an average roller coaster ride, there will be mechanical forces such as a lift motor or a chain to help the roller coaster up a steep hill with little momentum. From there, gravity will take over.
As the coaster moves down, potential energy turns into kinematic energies. The more the coaster accelerates the bigger values of kinematic energy is being presented and at the same time, the value of potential energy decreases and react inversely. As the ride continues, the train of cars are continuously losing and gaining height. Each gain in height corresponds to the loss of speed as kinetic energy is transformed into potential energy. Each loss in height corresponds to a gain of speed as potential energy is transformed into kinetic energy. AND that's how a roller coaster works.
Thursday, November 4, 2010
How to add vectors
Vectors, simply put, are values that have direction and a magnitude. Velocity, acceleration, and displacement also determines the value of the vector. The addition of vectors can be summarized into 5 steps.
1. First, determine each of the vector's direction. If it's moving eastwards or upwards, it has a positive and if it's moving west or downwards, it's negative. If a component has a negative sign (-), its magnitude is subtracted, rather than added.
2. Then, visualize or draw the diagram of the vectors and make it into a triangle.
5. Finally, find the direction the vector is going. The direction will always be from the point of the
2. Then, visualize or draw the diagram of the vectors and make it into a triangle.
3. Next, we use the Pythagorean theorem "a² + b² = c²" to calculate the unknown side.
4. After finding the length of the missing side, find the angle using the "SOHCANTOA" rule to find the angle. Most of the time in vectors, Tangent is used most frequently. The equation will be θ=tan-1(b/a), where θ is the angle that the resultant makes with the x-axis or the horizontal.
Friday, October 22, 2010
Deriving Equation 4
- Deriving Equation 4: d=V2Δt-½aΔt²
Well, equation 4 is sort of different from equation 3 but they do share some same components, such as the triangle part. However, the rectangular part is the major difference. The purpose of equation 4 is to utilizes a larger rectangle to subtract the triangular part to find the trapezoid area.
In this equation, we can find out the area of the larger rectangle by substituting V2 as the height. So the equation would look like: d=V2Δt.
Finally, you need to subtract the triangular value from the value of the large rectangle to form the trapezoid. So the final equation looks like this:
d=V2Δt-½aΔt² ; D
Well, equation 4 is sort of different from equation 3 but they do share some same components, such as the triangle part. However, the rectangular part is the major difference. The purpose of equation 4 is to utilizes a larger rectangle to subtract the triangular part to find the trapezoid area.
In this equation, we can find out the area of the larger rectangle by substituting V2 as the height. So the equation would look like: d=V2Δt.
Finally, you need to subtract the triangular value from the value of the large rectangle to form the trapezoid. So the final equation looks like this:
d=V2Δt-½aΔt² ; D
Deriving Equation 3
- Deriving Equation 3: d=V1Δt + ½aΔt²
Our goal in this equation is to find the displacement. We can do that by finding the area of the trapezoid made by the slope and the x axis. The equation basically divided the area of the trapezoid into two parts: a triangle and a rectangle.
The formula for the area of a triangle is A= bh/2. If we apply to that equation for the values on the triangle on the graph, the equation would be d= (v2-v1)Δt /2. To simplify this equation, we can replace (v2-v1) with aΔt. So the new equation would look like
d=½ (aΔt )Δt
d=½ aΔt²
and there we have the second part of equation 3 and now we have to derive the rectangular part.
The formula for the area of a rectangle is A=lw. If we apply to that equation for the values on the rectangle on the graph, the equation would be d= v1(t2-t1). We can simplify this equation further by replacing (t2-t1) with Δt.
d=V1Δt and here we have the first part of equation 3.
Finally, we combine the two equations together and the result is d=V1Δt + ½aΔt² - equation 3. : )
Our goal in this equation is to find the displacement. We can do that by finding the area of the trapezoid made by the slope and the x axis. The equation basically divided the area of the trapezoid into two parts: a triangle and a rectangle.
The formula for the area of a triangle is A= bh/2. If we apply to that equation for the values on the triangle on the graph, the equation would be d= (v2-v1)Δt /2. To simplify this equation, we can replace (v2-v1) with aΔt. So the new equation would look like
d=½ (aΔt )Δt
d=½ aΔt²
and there we have the second part of equation 3 and now we have to derive the rectangular part.
The formula for the area of a rectangle is A=lw. If we apply to that equation for the values on the rectangle on the graph, the equation would be d= v1(t2-t1). We can simplify this equation further by replacing (t2-t1) with Δt.
d=V1Δt and here we have the first part of equation 3.
Finally, we combine the two equations together and the result is d=V1Δt + ½aΔt² - equation 3. : )
Wednesday, October 20, 2010
Translating Graphs Thingys
Graph 1
We 80 cm from the motion detector. We walked @ a constant speed... ok... tried to walk away @ a constant speed and we stopped. Then, we walked forward and stopped the rest of the graph.
Graph 2
k for this one, we started @ 3 m, we walked towards the motion detector for @ a constant speed for 3 secs and we stopped.@ 4 secs we continued to walk away and stopped @ 5 secs. Finally, we walked away from the motion detector @ a constant speed until 10 secs.
Graph 3
This is a velocity/time graph and it is probably one of the hardest to walk. From 0 to 2 secs, our motion was still. From 2 secs to 5 secs, we were @ a constant velocity of 0.5 m/s. From 5 to 7, our motion was still again. Finally, from 7 to 10 secs, we walked @ a constant velocity of -0.5 m/s.
Graph 4
Just when i thought it graph 3 was the hardest one to walk... here comes graph 4. I gotta say... this is the worst result we got in this experiment. Graph 4 is also a velocity/time graph. In the first 4 secs, the velocity increase constantly to 0.5 m/s. From 4 secs to 6 secs, the velocity 0.5 m/s. From 6 secs to 9 secs, the velocity, is about -0.4. @ 9 - 10 secs, our motion was still.
Graph 5
Graph 5 is a distance time graph. From start to about 3.5 secs, we moved away from the motion detector @ a constant speed. Then we stood still and started moving further away from the motion detector @ about 6.3 secs.
Graph 6
Graph 6 is another velocity/time graph. We moved @ a constant speed of about 0.2 m/s for the first 3 secs.
Then from 3 secs to 6.2 secs, our velocity was about - 0.4. For the rest of the graph, our motion was still.
Graph 2
Graph 3
This is a velocity/time graph and it is probably one of the hardest to walk. From 0 to 2 secs, our motion was still. From 2 secs to 5 secs, we were @ a constant velocity of 0.5 m/s. From 5 to 7, our motion was still again. Finally, from 7 to 10 secs, we walked @ a constant velocity of -0.5 m/s.
Graph 4
Just when i thought it graph 3 was the hardest one to walk... here comes graph 4. I gotta say... this is the worst result we got in this experiment. Graph 4 is also a velocity/time graph. In the first 4 secs, the velocity increase constantly to 0.5 m/s. From 4 secs to 6 secs, the velocity 0.5 m/s. From 6 secs to 9 secs, the velocity, is about -0.4. @ 9 - 10 secs, our motion was still.
Graph 5
Graph 5 is a distance time graph. From start to about 3.5 secs, we moved away from the motion detector @ a constant speed. Then we stood still and started moving further away from the motion detector @ about 6.3 secs.
Graph 6
Graph 6 is another velocity/time graph. We moved @ a constant speed of about 0.2 m/s for the first 3 secs.
Then from 3 secs to 6.2 secs, our velocity was about - 0.4. For the rest of the graph, our motion was still.
Thursday, September 30, 2010
MOTOR assignment~!
Today in physics class, we had a challenge of building a functioning motor which is able to spin 2 cycles. my partner Keven and I had brought materials such as a wooden base, a kabob stick, 4 nails, a cork and some copper wires. Then as soon as the period start, both of us got right to work.
Here is Kevin hard @ work... i actually dun hav a pic of me doing
work... but i did do work 2 lol
After about 50 minutes of hard work, this is wat our final product looks like...
I know... shes beautiful...
Woooow... is Kevin really tat much taller than me?!
And finally our result...
Today in physics class, we had a challenge of building a functioning motor which is able to spin 2 cycles. my partner Keven and I had brought materials such as a wooden base, a kabob stick, 4 nails, a cork and some copper wires. Then as soon as the period start, both of us got right to work.
work... but i did do work 2 lol
After about 50 minutes of hard work, this is wat our final product looks like...
And finally our result...
If ur too lazy to watch the vid.... it worked
In conclusion, we successfully built a motor and i reallyyyy enjoyed the challenge... hope tat theres more fun projects like one this in the future.
Wednesday, September 22, 2010
Notes on magnetics
1. A magnetic field is a region which attracts magnetic forces.
2.There are two different forces, which are north and south.
3. We can use a test compass to find out the direction in which the north seeking pole of this compass would point at the point in space.
4. The metals that attracts magnetic forces are called ferromagnetic metals. All magnets are made of ferromagentics.
5. Domain theory of magnets Domain theory of magnets states all large magnets is made up of many smaller rotating magnets called dipoles. If dipoles line up, a magnetic domain is produced.
6. Right hand rules is a way to determine how magnetic forces is functioning. There are three right hand rules in total.
7. Oersted's principle states that change moving through a conductor produces a circular magnetic field around the conductor.
8. Right hand rule # 1 is used for conventional current flow. See image for instructions
9. The second right hand rule is used for coils. See image for instructions
10. The strength of a magnet can be adjusted by using the opposite magnetic field (B).
2.There are two different forces, which are north and south.
3. We can use a test compass to find out the direction in which the north seeking pole of this compass would point at the point in space.
4. The metals that attracts magnetic forces are called ferromagnetic metals. All magnets are made of ferromagentics.
5. Domain theory of magnets Domain theory of magnets states all large magnets is made up of many smaller rotating magnets called dipoles. If dipoles line up, a magnetic domain is produced.
6. Right hand rules is a way to determine how magnetic forces is functioning. There are three right hand rules in total.
7. Oersted's principle states that change moving through a conductor produces a circular magnetic field around the conductor.
8. Right hand rule # 1 is used for conventional current flow. See image for instructions
10. The strength of a magnet can be adjusted by using the opposite magnetic field (B).
Wednesday, September 15, 2010
Notes on Resistance, Ohm's law
Through the past two weeks of blogging, i found a major problem with this thing... I CAN'T UPLOAD ANY PICS~~~~! But just yesterday, i discovered from Young tat I've been writing in HTML mode. DD : Anyways, here's my notes, WITH SOME PICS. 1) Current flow depends on 2 two major factors: the potential difference of the power supply and the nature of the pathway through the loads that are using the electric potential energy.
3) We can calculate resistance by using the following formula: R (Resistance) = V (Voltage) / I (Current)
4) Ohm's law is the ratio of Voltage over Current. As we found out with our lab, as the current increase, so does potential difference. Vise versa, if the current decreases, so will the potential difference.
5) Factors that can determine the resistance of a conductor would be the likes of length, crossed-sectional area, material it is made of and its temperature.
6) The gauge # of a wire signals its crossed section area.
7) In a series circuit, the loads are connected one after another in a SINGLE path. In parallel circuits, they are side by side.
8) Kirchhoff's current law: the total amount of current into a junction point of a circuit equals the total current that flows out of the same junction. This law can be represented by the following equation: I1+I2+I3=IT=I4=I5
9) Kirchhoff's Voltage law: the total of all electrical potential decreases in any complete circuit loop is equal to any potential increases in that circuit loop. This law can be represented by the following equation: VT=V1+V2+V3
10) Laws of conservation of electric charge and the conservation of energy states that in any circuit, there is no net gain or loss of electrical charge or energy.
Monday, September 13, 2010
12 Mind-blowing Questions
1a)Can you make the energy ball work?
Yes, i can by putting my fingers on the two metal plates.
1b)What make the ball flash and hum?
The completion of the circuit makes the ball flash and hum. Current flowed thorough my body as i took the role of the conductor.
2. Why do you have to touch both metals contacts to make the ball work?
I have to touch both metals contacts to make the ball work because tat way, the circuit is complete.
3. Will the ball light up if you connect the contacts with any materials?
It will light up if it's connected with good conductors such as metals.
4. Which materials will make the energy ball work? Test your hypothesis
The metals rings on our binder made the ball glow. The metal zipper on my bag was also successful.
5. This ball does not work on certain individual what could cause this to happen?
Some people lack elements such as iron, copper or zinc in their body. Therefore, it would not make them good conductors. However, i do not believe that they are completely incapable of making the energy ball function. So basically... yea... i dun get it : (, but tat was my best guess.
6. Can you make the energy ball work with all 5 ~ 6 individuals in your group? Will it work with the entire class?
Yes, it works with 5 ~ 6 individuals and for the entire class, as long as it's a complete circuit.
7. What kind of a circuit can you form with one ball?
We can form a simple circuit.
8. Given 2 balls (combine 2 groups): Can you create a circuit where both balls light up?
Yes, we can by formulating a parallel circuit.
9. What do you think will happen if one person lets go of another person's hand and why?
It will break the circuit, causing the ball to not light up.
10. Does it matter who lets go?
In a simple circuit, as long as one part of the circuit is broken, the whole thing will not work. However, in a parallel circuit, if one person lets go, only one ball stops to light up, the other one, functions normally.
11. Can you create a circuit where only one ball lights up?
Yes, you would have to create a parallel circuit.
12.What is the minimum number of people required to complete this?
1 person i guess... but he gotta have long fingers and mad skillz.
Yes, i can by putting my fingers on the two metal plates.
1b)What make the ball flash and hum?
The completion of the circuit makes the ball flash and hum. Current flowed thorough my body as i took the role of the conductor.
2. Why do you have to touch both metals contacts to make the ball work?
I have to touch both metals contacts to make the ball work because tat way, the circuit is complete.
3. Will the ball light up if you connect the contacts with any materials?
It will light up if it's connected with good conductors such as metals.
4. Which materials will make the energy ball work? Test your hypothesis
The metals rings on our binder made the ball glow. The metal zipper on my bag was also successful.
5. This ball does not work on certain individual what could cause this to happen?
Some people lack elements such as iron, copper or zinc in their body. Therefore, it would not make them good conductors. However, i do not believe that they are completely incapable of making the energy ball function. So basically... yea... i dun get it : (, but tat was my best guess.
6. Can you make the energy ball work with all 5 ~ 6 individuals in your group? Will it work with the entire class?
Yes, it works with 5 ~ 6 individuals and for the entire class, as long as it's a complete circuit.
7. What kind of a circuit can you form with one ball?
We can form a simple circuit.
8. Given 2 balls (combine 2 groups): Can you create a circuit where both balls light up?
Yes, we can by formulating a parallel circuit.
9. What do you think will happen if one person lets go of another person's hand and why?
It will break the circuit, causing the ball to not light up.
10. Does it matter who lets go?
In a simple circuit, as long as one part of the circuit is broken, the whole thing will not work. However, in a parallel circuit, if one person lets go, only one ball stops to light up, the other one, functions normally.
11. Can you create a circuit where only one ball lights up?
Yes, you would have to create a parallel circuit.
12.What is the minimum number of people required to complete this?
1 person i guess... but he gotta have long fingers and mad skillz.
Thursday, September 9, 2010
blog 2: activity reflection
1. The reason tat our structure was not successful is because that the physics aspect was not successful. First, out base was not strong enough to support the whole weight of the structure, therefore causing it to constantly topple over. We also did not distribute the weight equally for the body of our structure and parts of it were under excessive stress causing the structure to bend and fall over. Overall, it was not a very successful attempt :"(.
2. i think the most important part of making a tall structure stable is to have a secure and stable base because it has to support the whole weight of the structure. Also, you have to make sure the weight of the body of the structure is even distributed so it doesn't topple over.
3. The centre of gravity, also known as centre of mass, is a point in an object which the whole body's mass is concentrated. It is a geometric property of a structure. It is important because it determines the balance of the whole subject.
2. i think the most important part of making a tall structure stable is to have a secure and stable base because it has to support the whole weight of the structure. Also, you have to make sure the weight of the body of the structure is even distributed so it doesn't topple over.
3. The centre of gravity, also known as centre of mass, is a point in an object which the whole body's mass is concentrated. It is a geometric property of a structure. It is important because it determines the balance of the whole subject.
Wednesday, September 8, 2010
blog 1: notes on current electricity
11 points on current electricity:
1. When electrons repel against each other, it creates energy. Through a conductor, this energy has many uses such as providing energy for various electronic applications.
2. When the charge is transferred from the conductor, the flow of the is called electric current.
3.In some ways, electrons flowing in a conductor is a lot like water flowing in a water-pipe.
4. The rate of current can be calculated with the following equation:
I(current in amperes) = Q(charge in coulombs)/ t(time in seconds)
5. Conventional current assumes the current flows out of the positive terminal. But in reality, this idea is wrong. The current actually flows out of the negative terminal and enters through the object's positive terminal. http://www.mi.mun.ca/users/cchaulk/eltk1100/ivse/ivse.htm
6. A way of measuring current is by using an ammeter. You must make the ammeter a part of the circuit in order to measure the current and the ammeter must be a very good conductor so the energy do not escape from it.
7. In a direct current, electrons flows in one direction but in an alternating current, electrons sometimes travels backwards.
8. http://www.kpsec.freeuk.com/symbol.htm (a site all about Drawing circuits and circuits symbols)
9. The electric potential difference can be calculated with the following equation:V (potential difference)= E(energy) / Q (charge)
10. A measuring device for potential energy difference would be a voltmeter. A voltmeter needs to be connected with a load in the circuit in order to function. Unlike a ammeter, a voltmeter must have a great resistance for the energy passed on to the object to minimize the current diverted in the circuit.
11. electricity, transfer of energy and convection is all very useful to meteorologists.
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