- 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
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