types of energy? :P

 well... i found these 5 major energies which I'm going to describe. we learned about potential energy and kinetic energy already in class... so I'm not going to describe that.

Gravitational Potential Energy
 well, based on the name, i think one can already guess that this is the type of energy that gravity generates. since gravity is the forcing pushing us down, the gravitational potential energy is related to pushing the objects down. since work is done when something is lifted, the force times gravity will equal to gravitational potential energy.


Mechanical Kinetic Energy
 Well, it is actually difficult to define this one... Mechanical energy is the energy required to do work. and kinetic energy is the energy of motion. both of them combined is basically the energy required to do work such as motion. Walking and running is considered motion.

Chemical Potential Energy
This type of energy is the type of energy the food that human eats transfers into energy. the human body's acid in our stomach dissolve the food then it is transformed into Chemical Potential energy to have energy to work for the day, do the homework and finish the tests with enough energy for the next class! :)

Thermal Energy
 This type of energy is the energy which heat generates. the heat all stocked up will create energy. the amount of energy can be measured by the equation Q=MC∆T  where the amount of heat transfer (J) which is equal to mass (kg) x heat capacity (J/kg ◦C) x change in temperature (◦C).  Thermal energy can be transferred using one of these three methods: conduction, convection and radiation. 


Sound Energy   
Sound energy is caused by the vibration of the sound waves. The sound vibrations create waves of pressure which leads to compression of the sound waves. then the pressure causes the vibration to cause sound waves. but this type of energy is usually too small to cause electricity. 

the canon report

Well, first, in order to maximize the canon's shooting range, we will need it to be in a 45 degree angle. that will make the canon shoot the furthest. however, that is if there is no air resistance and wind affecting the light light canon ball we were FORCED TO USE STYROFOAM TO BUILD >:( sigh, so anyways, without wind patterns there should be no problem with the ball shooting its maximum range.

Also we use this equation: R = V²sin(2θ)/g to calculate it. We determine the value of θ to be sin(2θ) since we are assuming v and g do not change... Well, we need it to be sin 90 which means they need it to be a 45 degree angle.

Newton's problems... well not his problems but his problems to the world- ehhhh you know what i mean >:(

First of all, The 4 problems are Equilibrium, Inclines, Pulleys and Trains(not the band, actual trains :))

- They all need assumptions
For Equilibrium- No Friction and a=0
For Inclines- positive direction of motion, a=0, no resistance
For Pulleys- No friction, no resistance, 2 FBDs
For Trains- 3 FBDs, No resistance, a=0 and constant, horizontal and positive motion

Example from my notes!-(sorry about it being sideways, its the only way to take the picture :( )
Equilibrium-

 Inclines-

 

Pulleys-

 Lastly, Trains-

Two in one- Vector addition AND physics of a Roller Coaster

 Physics of a Roller Coaster

Well a roller coaster works because of two principles, Kinematics and Dynamics. First of all we have to understand Newtons three laws:

Newton's first law- law of inertia : All objects will remain in a state of rest or continue to move with a constant velocity unless acted upon by an unbalanced force.

Newton's second law : The acceleration of an object depends inversely on its mass and directly on the unbalanced force applied to it.

Newton's third law : For every action force, there is an equal and opposite reaction force.


 Those laws would prove that Roller coasters have force applied on them in order for them to move. With a force of gravity acting against and along with it, the roller coaster is able to gain speed to fulfill the entrainment which people require for amusement. So we see Newton's first law applied as the roller coaster does not move unless there is a chain dragging it against gravity, and gravity acting on it as it goes down. Then we see Newton's second law as the weight of the people on the coaster and the coaster itself will affect the free fall or the fall of a roller coaster. Lastly, we see Newton's third law as for the against gravity movement, there is a along gravity movement.

Vector Addition

Vector addition is the addition of vectors. You basically need to understand that you are adding the directions along with the length. So first, before we move on to an example, you need to recall the Pythagorean Theorem which is A^2 + B^2 = C^2

 The vector addition is similar to that, because it is just one unknown side (usually the hypotenuse) then two known sides, which then will lead to the square of the two known numbers followed by the addition of both known numbers.

whoops almost forgot :P. deriving equations 3 and 4!

So Equations 3 and 4 are basically what Mr.Chung calls "Twins" so they are basically the same except that one is  V_{1 and the other is} V₂


How to transform from Equations 1 and 2 to Equations 3 and 4:
Equation 1: V₂₌ V_1+at
Equation 2: d= ^1/₂  (V₂ -V₁ )t

3:

Sub (at) for (V₂ -V₁ ) from equation 2_: d= ^1/₂  (V₂ -V₁ )t   +    V₁ t

 d= ^1/₂  (at)t   +    V₁ t

  d= ^1/₂   a t²   +    V₁ t

 d=  V₁ t  +   ^1/₂   a t² 

4:

d= V₂ t - ^1/₂  (V₂ -V₁ )t
Sub (at) for (V₂ -V₁ ) from equation 2
d= V₂ t - ^1/₂  (at )t
d= V₂ t - ^1/₂  a t²

The graphs but switched....i drew them...

• This is the distance-time graph
• From the start, the object moved away from the starting point [E] by constant speed
• Then, it stopped for a while and walked towards the starting point [W] for few seconds
• Then, it stopped for the rest of motion
• 
  

• This is velocity-time graph
• The velocity was 0 for 2 seconds , this is the stopped motion
• The velocity was 0.5 after 2 seconds until 5 seconds ; this is the walking motion [E]
• The velocity was 0 at 5 seconds until 7 seconds; this is where there is no motion
• The velocity was -0.5 until ends ; this is the walking motion [w]

• velocity-time graph
• At first, the velocity was increased 0 to 0.5 until 4 seconds; this is the speeding motion [E]
• From 4 sec the velocity was constant until 6 seconds ; this is the constant speed movement [E]
• From 6 the velocity was -0.4 until 9 seconds ; this is the slower speed movement[w]
• Then, the motion stopped from 9 seconds.

• distance-time graph
• It started from 1 m , moved constant speed until 3seconds ; this is moving [E]
• Then from 3 to 7 seconds,  this is the rest motion 
• Then from 7 to 10 seconds ; this is the moving constant speed movement [E] 

• velocity-time graph
• At first the speed [E]was constant until 3 seconds and 4 seconds to 7 seconds, the speed was [W] constant then the motion stopped from 7 seconds

• This is distance-time graph , it started from 3 meters , this is the constant speed [W]
• Then it moved 3 seconds from rest motion until 4 seconds
• Then it moved 4 seconds at constant speed [W] until 5 seconds
• Then it moved 5 seconds at rest motion until 7 seconds
• Then it moved 7 seconds to 10 seconds at constant speed [E] to 3meters.

building motors with Tomeo and James :D

At first i found the process difficult due to our lack of supplies. However after Mr. Chong entered the room with all the supplies that we need, i was confident that we would succeed. we decided to work separately for the process to speed up. Our motivation was the bonus mark Mr. Chong mentioned for who finished first. It was much easier than i anticipated, the nails go in the wood easily and the cork was soft enough for me to place the commuters and the axle. the nails had to be 2 or 3 cm apart for one side. on the other side, there needed to be a distance of 5-6 cm apart. While i finished up the board, James finished sanding his coke can. then i used a small nail to make holes for the 2 paper clips. the paper clips were the support for the axle. Then when the cork was placed on the paper clips, and it was stable; we nailed the tin can strips on the sides of the board in front of one of the paper clips. Lastly, James wrapped the coil around the cork vertically and we sanded both ends so that it touches the can strips. In the end, we succeeded in being the first group to accomplish the difficult task. Our motor spun 4-5 times on the first trial. Here are pictures of our beautifully created motor:

 

Well we are also the first group to make our motor explode! enjoy this video of our motor working(almost) and another of our motor exploding! (almost)

Right Hand Rules #1 & 2

-Right-hand rule #1 (conductors)-

First make sure that your thumb of your right hand points in direction of conventional current flow, then make sure your fingers are pointed in the direction of circular magnetic field around conductor.



-Right-hand rule #2 (for the coil)-

First make sure that your curled fingers of your right hand points in the direction of conventional current flow, then your thumb has to point in the direction of the magnetic field around conductor.

P. 582-589 notes

The magnetic force

-Magnetic field is the distribution of a magnetic force in the region of a magnet.

-Magnets also attract Ferromagnetic Magnets which are iron, nickel and cobalt.

-Demagnetization is when the Ferromagnetic materials lose their magnetic strength.

-Reverse magnetization is the polarity of magnets reversed.

-Breaking of a large magnet is breaking large magnets into smaller magnets.

-Maximum strength is a magnet which can only become so strong and no more.

-The Domain theory of magnet states that large magnets are composed of smaller magnets which are rotatable. Rotatable magnets are known as Dipoles.
-domains that are pointing in random directions can be alligned if they are placed in a large field with a fixed direction.
-domains could lose their order and point in different directions, causing a dilution and overall weakening of the magnet.
-Large magnetic fields pointing in the opposite direction cause all the domains to line up with the new field, reversing the overall magnetic polarity.
-In all the pieces, the domains still line up, so each acts like its own magnet.
-Once all the domains are aligned, there is no way to increase the magnet's strength any further.

- Normal magnets can never be shut off. However, scientists created the Electrical Magnet which can be shut off at will.

-Oersted Principal- Charge moving through a conductor produces a circular magnetic field around the conductor.

-The Right hand rule are several hand signs to help you predict how magnetic forces act.

-The 2 right hand rules:

Conventional flow #1- use your right hand pointing in the direction of conventional or positive (+) and the curved fingers point in the direction of the magnetic field around the conductor. This shows how it can predict the direction of the magnetic field around a straight conductor.


Conventional flow #2- use your right hand with curved fingers pointing in the direction of conventional or positive (+), current flow. the thumb points in direction of the magnetic field within the coil. Outside the coil, the thumb represents the north (N) end of the electromagnet produced by the coil. This predicts the relationship between the direction of conventional current flow in a coil and the direction of the magnetic field at the end of the electromagnet.

Chpt 16 notes. page- 553-563

The amount of energy transferred to any useful device depends on two things:

-The potential different of the power supply (the amount of push).

-The nature of the pathway through the loads that are using the electric potential energy.

Volt & conductivity can determine the amount of current flow.

Equation for Ohm's law: R(Ω) = V(V)/I(A) 

 

R: Resistance, measured in ohm (Ω)- is the opposition of flow and can make the pathway in a circuit more difficult to flow.

 

V: Voltage, measured in volt (V)- determines the amount of current flow.

 

I: Current, measured in amperes (A)-  is a flow of electricity through a conductor.

Superconductivity: Ability of a conductor conducting electricity without heat loss due to resistance. The highest temperature it can reach is (-133°C)

 

Factors which affect Resistance can be Length- by how long it is, it affects how great the resistance is. Cross-sectional area- by how thick or large it is, there will be less resistance. Materials used- not everything are conductors, so what is used can affect it. Lastly, Temperature- as you may be aware of, matter separate once it is heated up, so higher temperature increases resistance.

 

Kirchhoff’s current law: The total amount o f current into a junction point of a circuit equals the toal current that flows out of that same junction

 

 

 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.

 

Kirchhoff’s law: 

 

Ohm’s law: R=V/I,

Chart

 

Name

Symbol

Unit

Definition

Voltage	V	Volt(V)	The electrical potential energy for each coulomb of charge in a circuit.
Current	I	A	A flow of electricity through a conductor.
Resistance	R	Ohms(Ω)	A measure of the opposition to current flow.
Power	E	Watt(W)	The rate of which work is done. ©Tomeo®

Difference between a series circuit and a parallel circuit.

Series Circuit:

A series circuit is a circuit that only goes in one direction without any resistors going through the middle. However, if any resistor goes out, then everything will not work.

A series circuit is a closed circuit and it is joined, so every individual resistor would get their power faster.









Parallel Circuit:

A parallel circuit is when all the resistors are in separate rows. it is good because if one resistor is burnt out, the other resistors are still functioning.

A parallel circuit is not joined so it would take longer to reach every individual resistor. A parallel circuit is also a closed circuit.

Energy Ball Questions

Q1a. Can you make the energy ball work?
Yes, we can make the ball work by placing our fingers on the metal plates

Q1b. What makes the ball flash and hum?
Since there is a hole in between the two metal plates, we each need two fingers that is connected to connect the circuit.

Q2. Why do you have to touch both metals contacts to make the ball work?
Our fingers which acts as conductors to allow the electrons to run through our body to connect the circuit.

Q3. Will the ball light up if you connect the contacts with any materials?
No, not every object act as a conductor.



Q4. Which materials will make the energy ball work? Test your hypothesis
Certain objects which act as conductors. For instance, salt water and metal.

Q5. This ball does not work on certain individual what could cause this to happen?
That event occurs when only one side of the metal plate has been touched. Or if you are nor charged enough, because of contact with positive or negative charges. And you need to keep giving electrons to it from stealing electrons from others.

Q6. Can you make the energy ball work with all 5 ~ 6 individuals in your group? Will it work with the entire class? It does work, the currents just connect through all of us. It will work with the entire class as long as we are all connected.

Q7. What kind of a circuit can you form with one ball?
A series circuit, because it only goes in one direction.

Q8. Given 2 balls (combine 2 groups): Can you create a circuit where both balls light up? [1/3]
Yes, we can create a circuit.

Q9. What do you think will happen if one person lets go of another person's hand and why? [2/3]
It does not connect so the circuit is opened.

Q10. Does it matter who lets go? Try it. [3/3] No, if one of us lets go, it doesn't work.

Q11. Can you create a circuit where only one ball lights (both balls must be included in the circuit)? [1/2]
Yes, using a parallel circuit.

Q12. What is the minimum number of people required to complete this? [2/2]
At least one person.

challenge!

The physics of tall structures:

A tall structure must have a stable and strong base. The reason to that is because the base must always be heavier than the top. Since gravity is 9.8 m/s, the heavier the top is, the easier it is for the structure to collapse. Known from the equation-

And also:

We can understand how to calculate the structure stability from gravity. But also there are other factors such as the wind, that can not be calculated... but we can understand how stable a tall structure is using the wind. You must first understand that the wind can be quite strong, so it can blow down a structure if it is weak. We can prevent that from happening may be to make all the parts tight together. We can also calculate the potential energy of a tall structure by using the formula- Eg= mgh... but that is off topic.

What makes a tall structure stable?-

Tall structures have the disadvantage of being too unstable due to gravity (as shown above) but one thing which supports it greatly is the base. A strong base can contribute to many tall structures. For example, the CN Tower,  it becomes more narrow as it extends to the top. That makes it stable and tall.

What is the center of gravity?

The center of gravity is usually the point where the structure balances. That point would be the central point of a structure, even though it's called the center of gravity, it doesn't necessary have to be in the middle. The center of gravity can be slightly below the exactly middle of the building. The reason to that is because the base is much wider than the narrow part, so the center of gravity must be where two parts of a structure has the same weight. In that case where the base is the widest in the structure; the center of gravity is lower than the exact middle of the structure.

page 544-522 notes

1. I is the symbol for current and it is measured in A(ampere).
Q is the total amount of charge moving past a point in a conductor and is measured in coulombs(C).
t is the time taken to complete the process.

2. Q=Ne or N=Q/e
Q is the charge moving past a point in a conductor.
N is the number of electrons passed through Q.
e is the charge of one electron.

3. An ammeter measures the currents and it must be wired to all devices to be functional for current to flow through it.


4. Conventional current is the positive charge.

5. Direct currents flow in a single direction until it reaches it's destination.

6. The destination which consumes the energy from the Direct currents is called a load.

7. The alternating current is a current going in the direction reversed to which way it should flow to by using electrical or magnetic forces.

8. A circuit is the path of a current which helps the current flow from it's negative to it's positive side.

9. The electrical potential difference is symbolised as V using the equation:

V= E/Q

Q is the electrical potential of a charge.
E is the energy required to increase Q.
V is the potential difference.

10. Since V= E/Q , I= Q/T

E= VQ, Q=It









therefore E=VQ
                 =VIT
11. VIT is used to calculate the amount of joules of energy used.