Different Types of Energy

Chemical potential energy：

Chemical potential energy is a form of potential energy related to the structural arrangement of atoms or molecules. Chemical energy stored in the chemical bonds of matter. Chemical reaction is transformed by chemical energy of chemical substance.

Gravitation potential energy:

Gravitational potential energy is stored in the gravitational field, due to its height in an area above the surface of the Earth, where the force of gravity can act on it to make it fall.




Elastic potential energy:


Elastic potential energy is the energy stored by the bending, stretching or compressing, stored deformation of an elastic object, such as the stretching of a spring.




Mechanical potential energy:

Mechanical energy is the energy that is an object due to its motion or due to its position. Mechanical energy can be either kinetic energy (energy of motion) or potential energy (stored energy of position). Objects have mechanical energy if they are in motion or if they are at some position relative to a zero potential energy position.




Thermal energy:


Thermal energy is the energy that makes objects hot. It is a form of kinetic energy at the molecular level, the movements of atoms and molecules. For example, Hot water has more kinetic energy then cold water.




Sound energy:


Sound energy travel through a specific medium, the energy produced by sound vibrations. Sound vibrations because waves of pressure which lead to some level of compression. Sound energy is a form of mechanical energy; is not related to any chemical change, but is purely related to the pressure its vibrations cause.

CANNON !!

Cannon uses gunpowder or other explosive-based propellants to launch a projectile. The Jaivana cannon is the world's biggest wheeled cannon ever made. It is located in India. It was built in 1720, Jaivan rests on a high 4 wheeled carriage. The front wheels are 2.74 m in diameter and the rear wheels are 1.37 m in diameter. The length of the barrel of the cannon is 20 feet 2 inches and it weighs 50 tons. The circumference near the tip of the barrel is 7 feet 4 inches and that of the rear is 9 feet 4 inches. The diameter of the bore of the barrel is 11 inches and the thickness of the barrel at the tip is 8-1/2 inches. The thickness gradually increases towards the rear of the barrel. A 776 mm long elevating screw was used for raising and lowering the barrel. Reportedly, it took four elephants to swivel it around on its axis. The cannon uses about 100 kg of gun powder fired a shot ball weighing 50 kg. The uses and range of the cannon and cannonballs vary over different sources. Some say the Jaivana Cannon was only fired once by the Maharajah Jai Singh, as a test-fire in 1720. Others say that it was fired many times, indicated by the fire marks on the inside of the barrel. The most exaggerated was it had a range of 40 km with the Maharajah's test fire; other sources say it is 35, 22 and 11 km.

4 NEWTONS PROMBLEMS !!

Formulas：

F=ma   Fk=μkFn   Fs=μsFn

Equilibrium

There is no force when the force is balanced.

Assumptions:

-          no air resistance

-          no friction

-          a=0 ( ax=0 and ay=0 )

-          set positive axis

-          break down in to x and y components

-          Free Body Diagram

-          T1x=T2x

Inclines (Static) / Incline (Kinetic)

The object in on an incline surface, one is static has no acceleration and another one is kinetic with acceleration.

Inclines (Static) Assumptions:

-          no air resistance

-          FN  perpendicular to the surface

-          positive axis is the direction of acceleration

-          no acceleration

-          break down in to x and y components

-          Free Body Diagram

-          Fgx-f=0

-          FN-Fgy=0

Inclines (Kinetic)
Assumptions:

-          no air resistance

-          FN  perpendicular to the surface

-          positive axis is the direction of acceleration

-          break down in to x and y components

-          acceleration does not equal to zero

-          Free Body Diagram

-          FN-Fgy=0

-          Fgx-f=ma

Pulley

A pulley has two mass one is going up and one is going down, is used to change the direction of an applied force, the acceleration are the same.

Assumption:

-          pulley is frictionless

-          rope frictionless

-          no air resistance

-          Positive axis is the position of the

-          2 system, 2 Free Body Diagrams

-          T1=T2

-          Acceleration of the system is the same ay1 = ay2

-          break down in to x and y components acceleration

Trains

We assume the train as a whole.

Assumption

-          positive axis is the direction of acceleration

-          acceleration is constant

-          no air resistance

-          acceleration of the system is the same

-          ay = 0

-          3 Free Body Diagrams
-          T1y-T2y-Fg= 0

Projectile Motion

   Projectile motion is a two dimensional motions with constant acceleration.  The motion of an object projected into the air at an angle. For examples, when you are kinking a soccer ball, throwing a baseball, or a long jumping. When a projectile is an object upon which the only force acting is gravity.

There is no acceleration in Vx, gravity is the acceleration in Vy.

         

             Path of a projectile projected at an angle with horizontal direction.

Component projectile velocities in x and y direction,the Vx stays the same and moving at constant speed.

Four Types of Projectile Promblems:

Type 1:

Type 2:

Type 3:

Type 4:

Physics Behind Roller Coaster

Gravity is the driving force of a roller coaster. The train is pulled to the top by gaining potential, or stored energy. As the train is pulled to the top, the train is released from the top of the lift hill; it is the acceleration due to gravity that brings it back to the beginning, its velocity increases. This causes the train to gain kinetic energy, which is the energy of motion. The faster the train moves, the more kinetic energy the train gains. The train begins to climb the next hill and the speed start to decreases.

                                                
                                        The initial hill is the steepest in the entire ride.

Behemoth is my favorite roller coaster, it clear shows the gravity and potential energy and also velocity and kinetic energy.

Vector Addition

Two or more vector can be added together to determine the result, there is no minus sign in those in vector addition, if the vector going to the opposite direction, for example, North and South, we use North + South instead of North + (-North).

We use Pythagorean Theorem and head to tail method to determining the magnitude and direction of adding two or more vectors.

 

 

We use trigonometry to determine a vector's direction

                                                                   1 km [N 45°E]         

                                                         One kilometer 45°east of north

Derive of Equation #4

Derive of Equation #3

Hypothesis of the six Graphs

Divided each graph into different sections whenever it breaks.

Graph 1

Velocity: A horizontal line on the x-axis, constant velocity in the positive direction,
A horizontal line on the x-axis; a horizontal line goes to the negative direction below the x-axis and a horizontal line on the x-axis.

Acceleration: No acceleration, a horizontal line on the x-axis.



Graph 2:

Velocity: Constant velocity in the negative direction, rest, constant velocity in the negative direction, rest and constant velocity in the positive direction.

Acceleration: No acceleration, a horizontal line on the x-axis.



Graph 3:

Distance: A horizontal line on the x-axis, increasing velocity in the positive direction, moving in the positive direction at a constant velocity, slowing down in the negative direction and then rest, slowing down in the negative direction and constant velocity in the negative direction.

Acceleration: no acceleration, velocity relative to the positive direction is increasing, no acceleration, velocity relative to the negative direction is decreasing, no acceleration, velocity relative to the negative direction is decreasing and no acceleration.



Graph 4:

Distance: Increasing velocity in the positive direction, moving to the positive direction at a constant velocity, decreasing velocity in the negative direction and moving to the negative direction at a constant velocity.

Acceleration: Velocity relative to the positive direction is increasing, no acceleration, velocity relative to the negative direction is decreasing and no acceleration.



Graph 5:

Velocity: Constant velocity in the positive direction, a horizontal line on the x-axis, and constant velocity in the positive direction.

Acceleration: No acceleration, a horizontal line on the x-axis.



Graph 6:

Distance: Moving to the positive direction at a constant velocity, decreasing velocity in the positive direction, moving to the negative direction at a constant velocity, increasing velocity in the positive direction and a horizontal line on the x-axis.

Acceleration: no acceleration, a horizontal line on the x-axis, velocity relative to the negative direction is decreasing, no acceleration, a horizontal line on the x-axis, speeding up in the positive direction and no acceleration, a horizontal line on the x-axis.

6 walking Graphs

Graph 1

The motion started at 1 meter from the origin to the positive direction rested for 1 second, walked positive direction constant speed for 2 seconds, stopped for 3 seconds, walked toward the origin constant speed for 1and half seconds and then stopped.

Graph 2:

The motion started at 3 meters away from the origin, from the positive direction walked toward the origin at constant speed 0.5m per second, rested for 1 second, run toward the origin at constant speed 1 meter per second, rested for 2 seconds, and walked fast to the positive direction at constant speed.

Graph 3:

The object rested for 2s speed up for 0.1 second walked away from the origin, for 2.8 seconds at 0.5 meter per second, speed up toward the origin for 0.1 second then rested for 1.8 second, speed up 0.1 second walked away from the origin at 0.5 meter per second and kept the same speed.

Graph 4:

The motion became faster and faster away form the origin for four seconds and kept the same speed 0.5 meter per second for 2 seconds; speed up for 0.1 second walked away from the origin, at 0.4 meter per second and kept the same speed for 2.8 seconds, then speed up 0.1 second toward the origin and stop.

Graph 5:

The motion started at 0.85 meter away from the origin, walked away from the origin at constant speed 1.15 meter for 3 and half seconds, keep the same speed at 1 second per 1.9 meters 3 seconds and then speed up away form the origin at constant speed.

Graph 6:

The motion started at 0.35 meter per second away form the origin, walked at the constant speed for 3seconds, slow down, speed up and 0.1 second walked toward the origin, kept the same speed for 4 seconds, slow down, speed up and 0.1 second walked toward the origin and stopped.

Building an Electric Motor

  For -Building an Electric Motor-this project, our task was building an electric motor and make the motor spin, when it connects the power supply. Firstly, we hammered the four nails in to the wood, the distance between was 5cm×3cm. Secondly, we made the Axel went though the cork, there are two pins place into the centre of the each end of the cork, we sanded the end of two side of the wire and we wrapped the wire around one of the commutator pins and around the cork, other end of the wire it wrapped around the other commutator pin. Thirdly, we used the pop can for the brush but before we use it we had to sand it all over perfectly and used the thumbtack to make it staple. In addition, we used two paper clip bearings to hold up the axel, and make sure it could spin. Lastly, we put 2 magnets, one on each side, and connect the power supply made the motor spin.

Right Hand Rule #1 and 2

Right Hand Rule #1:

Current flow from positive to negative, the thumb of the right hand is pointing to the positive current flow and the curved fingers are pointing to the direction of the magnetic field around the conductor

It is the positive direction of the current flow

It is the negative direction of the current flow

Right Hand Rule #2 rules for coils:

In right Hand Rule #2 the Current flow from positive to negative.

Curved fingers around conductor, the curved fingers point the direction of positive current flow, and they represent the current. The thumb points the direction of the magnetic field and it represents the direction of the north.

The Magnetic Force P582~589

1. Magnetic field is the distribution of a magnetic force in the region of a magnet
2. There are two different magnetic characteristics: north and south are responsible for magnetic force
3. Similar magnetic poles they repel one another, dissimilar poles they attract one another

4. Iron, nickel, and cobalt are ferromagnetic metals

5. All magnets are made from Iron, nickel, and cobalt

6. Magnetic material as composed of many small magnets and is called to domain theory of magnets

7. Domain Theory all large magnets are made up of small and rotatable magnets, called dipoles, therefore they can interact with other dipoles close to each other.

8. If dipoles lines up, a small magnetic domain will be produced

9. Oersted’s Principle: a circular magnetic field around the conductor produces when charge moving through a conductor

10. There are three Right hand rules, which involve using our hand, they abbreviated as RHR.
11. RHR #1 conventional current flow, straight thumb along conductor.

12. RHR #2 right hand rule for coils, curved fingers around conductor

10 POINTS FROM P553~563

1. (1) the potential difference of the power supplies (2) the nature of the pathway through the loads are the two things of the amount of current flow in a circuit and the energy transferred to useful device.

2. Two of the simple circuit, the first circuit allows the circuit to pass though the load easier than the second circuit, in the two circuits, their potential difference is the same, but the pathways are different.

3. The more difficult the pass, means the more opposition there is to flow. Electrical resistance is the measure of this opposition to flow.

4. R is the resistance in volts/ampere, Ohm（Ω）is the unit of the resistance.

5. V/I this ratio is called Ohm’s law

6. The resistance of a conductor depends on 4 major things: its length, cross-sectional area, material, and its temperature.

7. Series circuit and parallel circuit are the two simplest ways to connect conductor and loads.

8. In a series circuit the loads are connected one after another in a single path

9. In a parallel circuit the loads are connected side by side

10. Kirchhoff’s current law: the total amount of current goes into a junction point equals the same amount of current that flows out of that same junction.

                                           

11. Kirchhoff’s voltage law: the total amount of potential decreases in any complete circuit loop is the same number as the electrical potential increases in that circuit loop

12 . Vt = V1+V2+V3 so, there is no gain or loss of electric charge or energy in a circuit.