Physics

Impulse and Momentum

momentum is the tendency of an object to continue moving.

A semi-Truck going down a hill at 70 mph will have a much more momentum than a smart car going down the hill at 70 mph

Impulse is the change in momentum of an object being acted upon by another force.

An example of impulse is when you throw a tennis ball at a wall and the ball bounces back. The energy from the moving ball is transferred back to the ball from the wall to the ball so it bounces backwards.

A slow objects with a large amount of mass can have to same momentum as a fast object with a low amount of mass.

Friction

Friction is the resisting forces when to objects encounter each other while moving

Most of the time friction results in the release of thermal energy.

Friction welding machines can use extremely powerful motors to grind two pieces of metal together. The friction causes the metal to heat up drastically welding the two pieces together.

When you press the breaks in your car, friction is what brings the car to a stop at the stop light.

Gravity

Gravity is a force that is present with all mass, the more mass an object has, the stronger than gravity of the object

When parachuting out of a plane, you will always far towards the ground because the Earth's is stronger than the gravity of any other near by objects.

Gravity get much weaker as you travel farther and farther away from the source of the gravity.

Gravity accelerates objects at a speed of approximately 9.8 meters per second, per second.

Newtons laws of motion

1st law an object at rest tents to stay at rest

3rd law every action has an equal and opposite reaction

2nd law Acceleration is created when a force is applied to mass F=M*A

When I was driving down a hill, the car began to accelerate because the slope let the gravity pull the car forward faster and faster. The car would have continued to accelerate until it met with friction from air or from the ground.

Energy

Kinetic Energy

Kinetic energy is energy from and object in motion traveling with a certain mass and speed.

Thermal Energy

Thermal energy is energy in the form of heat.

Law of conservation of energy

energy cannot be created or destroyed, it can only be transformed from one type to another.

Total Energy

Total energy is the overall sum of all energy being used

total energy will remain constant so long as all forces are contained to the system

Potential Energy

Potential Energy is energy possessed by an object giving it's placement and or location.

mechanical waves

a mechanical wave refers to any type of matter that travels through a physical medium.

when a pebble is throw into a pond, the ripples of water traveling outward from the splash are an example of a mechanical waves. The energy from the rock is transferred to the water and it moves outward until is finally dissipates

I trumpet is an example of a mechanical wave because the air passing through the metal creates sounds. This is an example of an open ended wave.

A piano creates mechanical waves because the strings vibrate when they are struck by the hammer. This is also an example of a closed ended wave.

Changes in pitch and volume

Doppler effect is a phenomenon in which a wave's pitch increases or decreases if the source of the wave is traveling quickly toward or away from the receiver

volume is what the listener perceives as louder of softer sounds.

When someone tells you to turn the volume of the music down, they are referring to a generalized unit of sound rather than the specific amplitude of the sound

A common example of the doppler effect is when a emergency vehicle rushes by with it's sirens blaring and the sound sounds shifted.

Hearing

Hearing refers to a sense or ability to detect sound throughout the atmosphere and differences in pitch and amplitude.

superman posses super hearing which enables him to detect sounds from far away distances and at very high and low frequencies. This allows him hear very faint sounds through large structures and long distances.

When sound waves reach the eardrum, they cause the eardrum to vibrate. When the eardrum vibrates, it moves the tiny ossicles. From the hammer to the anvil and then to the stirrup. These bones help sound move along on its journey into the inner ear. The inner ear then converts these movements into electrical impulses which are then registered by the brain as sound.

Hearing is one of the most useful senses that certain living beings posses. It allows certain lifeforms to detect atmospheric disturbances around them. Bats use echo location to determine their course of travel. By sending out a sound and then listening for the way to bounce off of an object, the bat can then determine where things are around it.

Vision

Human vision is based mostly on visible light which lies beneath infrared and above ultraviolet wavelenghts.

When you turn on the lights at night, the reason they seem so bright is because your pupil has not adjusted to the different light level from the darkness.

The light enters the cornea and bends the light entering the eye, then the light goes through the pupil where the brightness is controlled, light then passes through the lens of our eye where it is refracted, the light then hits the vitrus fluids, light is then absorbed by the photo receptors in the retina when it is converted to electrical impulses, the optic nerve then carries that information to the visual cortex of the brain.

Changes in color and brightness

The change in the color of an object is the result of different wavelengths of visible lights. Dark blue is around 400 nanometers and bright red is around 700 nanometers.

Brightness is the result of a increase in the amplitude of light, or the more energy produce by the object, the higher amplitude of the light.

Magnetism

Magnetism is a physical phenomenon in which the motion of an electric charge, creates attractive and repulsive forces between objects.

Inside of hard drives and computer storage, computes use very precise magnets to manipulate the position of electrons inside of the disk. Every one of these electrons represents a number in binary which can them be translated into useable data by the computer

Many remote control cars will use brushless motors to power the vehicle. A brushless motor is a motor that uses permanent magnets on the on the rotor, which than an electromagnet pushes the motor cause it to spin.

There are many types of magnetism including, Diamagnetism., Paramagnetism, Ferromagnetism, Antiferromagnetism, Ferrimagnetism, Superparamagnetism. Magnetic monopoles.

Electricity

Electricity is a form of energy resulting from the existence of charged particles (such as electrons or protons), either statically as an accumulation of charge or dynamically as a current.

Electricity can also travel in the form of a current. Usually the electrons are carried by a wire. In order for them to travel they need a battery to create a electric potential difference. A current also needs a closed conductive path in order to create a circuit.

Lightning is an very common example of static electricity. The charge is built up inside of the clouds by the friction between the gasses ans water molecules. The positively charges particles move to the top and the negatively charged particles move to the bottom. When a lightning strike happens, it is because of the electrons trying to create the closes source to the ground.

An example of static electricity is when you wear socks and bug them on a wool carpet. If you then touch some one you will release a static charge and shock them. This is because you accumulate charge and when you make contact with another person, the charge travels to them.

Electromagnetic waves

Electromagnetic wave are on the EM wavelength spectrum, which encompases cosmic rays, gamma rays, x-rays, ultraviolet-rays,visible light, infrared rays, micro waves ,and radio waves.

microwaves are commonly used it heat foods in a microwave oven. The frequency of the microwave disturbs the water molecules in food until they begin to produce heat and warm the food.

X-Rays can be used to penetrate human tissue and show the location of possible disturbances in the body. The X- Ray cannot penetrate bone, so it is very useful for determining the condition of the bones in the human body.

Radio waves are one of the most commonly used form of wavelength because of it's usefulness in communication. Radio waves are the longest of any type of wavelength, but in turn they can easily be blocked by the environment.