Wave Interference

Constructive wave, two waves in the same direction adding upon one another
Destructive wave, two opposite direction waves cancelling each other out

Different Types of Energy

Chemical energy is a form of potential energy and it is possessed by things such as food, fuels and batteries. Chemical energy is one form of potential energy, along with mechanical energy, gravitational energy, nuclear energy and electrical energy. All of these forms of energy are stored within an object and are converted to forms of kinetic energy when a force or change is applied. During chemical reactions, molecules can be created or destroyed. If a product is created, the chemical energy is stored in the bonds that make up the molecules. If something is broken down, the chemical energy is released, usually as heat. If a reaction releases energy, it is called exothermic, and if it absorbs energy, it is called endothermic.

Mechanical energy is the sum of energy in a mechanical system. This energy includes both kinetic energy, the energy of motion, and potential energy, the stored energy of position. Mechanical energy exists as both kinetic and potential energy in a system. Kinetic energy, the energy of motion, exists whenever an object is in motion.

Gravitational potential energy is energy an object possesses because of its position in a gravitational field. The most common use of gravitational potential energy is for an object near the surface of the Earth where the gravitational acceleration can be assumed to be constant at about 9.8 m/s². Formula: PE = mgh

Elastic potential energy is Potential energy stored as a result of deformation of an elastic object, such as the stretching of a spring. It is equal to the work done to stretch the spring, which depends upon the spring constant k as well as the distance stretched. Formula: PE = 1/2(k/x2). x is distance.

Thermal energy is generated and measured by heat of any kind. It is caused by the increased activity or velocity of molecules in a substance, which in turn causes temperature to rise accordingly. The laws of thermodynamics explain that energy in the form of heat can be exchanged from one physical object to another.

Sound energy is the energy produced by sound vibrations as they travel through a specific medium. Sound vibrations cause waves of pressure which lead to some level of compression and rarefaction in the mediums through which the sound waves travel. Sound energy is, therefore, a form of mechanical energy; it is not contained in discrete particles and is not related to any chemical change, but is purely related to the pressure its vibrations cause.

Cannons

On Thursday, the whole class will be making CANNONS!!! Boom! The whole cannon will only be made of maximum five pop cans. Three will be for the cannon itself and the other two will probably be the base. The best angle to set the cannon is at 45 degrees, which was proofed during projectile unit. The fuel will be ethanol and the "cannon ball" will be made out of a double Styrofoam cup. Duct tape will be used to secure everything together. The launch will be on Monday, hope it will succeed!

four Newton's problems

Newton's 3 Laws:

1. Law of Inertia - objects are lazy --> objects will remain their motion unless there's an extreme force

2. Force, Mass, Acceleration (F = ma)

3. For every action there's an EQUAL and OPPOSITE reaction

Equilibrium:

Assumptions:

- F = 0

- no friction

- no air resistance

- no acceleration

Incline:

Assumptions:

- positive is in the direction of  acceleration

- no air resistance

Pulley:

Assumptions:

- pulley is frictionless

- rope is frictionless

- no air resistance

- 2 systems --> 2 FBD

- T1 = T2

- ay1 = ay2

 

Train:

Assumptions:

- 3 FBD to find T

- no air resistance

- ay = 0

- cables weightless

- positive along acceleration

- acceleration is consistent

Projectile Motion

Type 1:

Type 2:

Type 3:

Type 4:

Physics behind roller coasters

Kinematics plays a huge factors in how roller coasters work. As roller coaster gain speed, the velocity increases therefore there is also an increase in kinetic energy. The faster a roller coaster is moving, the more kinetic energy it has. Due to this, kinetic energy is highest when the roller coaster is at the bottom of the track, while the kinetic energy decreases once the roller coaster starts to slow down.

Gravity is the acceleration that pushes the roller coaster down when it is descending. When the roller coaster is moving downwards, its acceleration increases because gravity is pulling the roller coaster down. When the roller coaster moves upwards, its acceleration decreases because gravity is working as an opposing factor.

I don't usually ride roller coasters. Actually I am not a fan of roller coaster, therefore there isn't one that I'm particularly fond of, so I don't have a favourite one.

How to add vectors

Fomulas:
Pythagorean: a² + b² = c²

Trigonometry:

Adding or subtacting vectors by scale diagram:

1. Head to Tail

2. Resultant is always origin to destination

3. subtracting vecotrs means adding a vector in the opposite direction

4. use protractor to mreasure the angle accordance to N or S

Adding or subracting vectors by Components:

1. Set your positive axes (N and E)

2. Break all vectors down into two components (x and y)

3. Solve for x and y

4. Use pythagorean to add the two sums of components (x and y)

5. Use trigonometry to solve for angle