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,