★★ FORCE - a push and pull exerted by one body on another body

TYPES OF FORCE:
Normal Force - a contact force applied by a surface on an object
Force of Gravity - pulls objects with mass towards each other
Friction Force -present when two surfaces are in contact with or move past each other; can resist sliding or rolling
Tension Force - transmitted through a string, rope, cable, or wire when it is pulled tight
Spring Force - exerted by a stretched or compressed spring
Applied Force - a force that is applied to an object by a person or another object

Motion - change in position of an object over time with respect to a reference point
Velocity - vector measurement of the rate and direction of Motion
Acceleration - the greater the force, the greater the acceleration; the rate at which velocity changes with time in terms of both speed and direction
Inertia - property of a body that tends to resist a change in its state of motion

The greater the unbalanced force, the greater the acceleration of the body being acted upon. Double the force, double the acceleration.
The greater the object's mass, the greater the amount of matter has to be accelerated.

NEWTON’S LAWS OF MOTION:
The first law (Law of Inertia) - states that a body will remain in its state of rest or constant-velocity motion as long as no unbalanced force acts on it

The second law (Law of Acceleration) - states that acceleration and net external force are directly proportional, and there is an inversely proportional relationship between acceleration and mass

The third law (Law of Interaction) - For every action, there is an equal and opposite reaction.

Joule - SI unit of energy; quantifies the amount of energy transferred when a force of one Newton moves an object one meter in the direction of the force; can also be understood as the energy required to produce one watt of power for one second.

Newton - SI unit of force; one Newton is defined as the amount of force required to accelerate a one-kilogram mass by one meter per second squared.

★★ WORK, POWER, ENERGY
Work - Product of force exerted and the distance through which the body moves; in layman’s terms, work means doing anything that requires physical labor; in physics, work is said to be done when a body or object moves with the application of external force. 

Power - The rate of doing work.
Energy - The ability to do work.
Potential Energy - A stored energy possessed by a body by virtue of its position.
Kinetic Energy - The energy of a moving body.

When work is done on an object: 
Energy is transferred from the object doing the work to the object having work done on it 
The object doing the work loses energy 
The object having work done on it gains energy

How much work is being done?
We can measure the amount of work being done to move an object 
We need to know 2 things to measure work:
1. The amount of force being used 
2. The displacement of the movement

Types of Displacement:
Positive - same direction as the displacement
Negative - opposite direction as the displacement

A positive work aids motion, thereby increasing the speed of the objects. If the applied force on the object and its displacement are perpendicular to each other, no work is done. Work can be done by lifting but not by holding or carrying them horizontally.

Energy: whenever work is done energy is transferred to that object; power is the rate at which the energy is transferred; energy also uses Joules as a unit
POTENTIAL VS KINETIC ENERGY:
Potential - object’s height or distance and mass (types of Potential Energy: Elastic and Gravitational)
Kinetic - object’s speed or velocity and mass

More Types of Energy:
Thermal Energy, Mechanical Energy, Nuclear Energy, Electromagnetic Energy, Electrical Energy, and Chemical Energy

★★ LIGHT AND SOUND
James Clerk Maxwell - Formulate the theory of electromagnetic radiation.

Light - Transverse and electromagnetic wave; travels in a straight line; travels away from its source in straight lines; when it hits an object, it reflects (bounces off) and travels in a new direction; if the reflected light enters your eyes, you can see the object.
SPEED OF LIGHT: 3 x 10^8 m/s

Wavelength - Distance between consecutive peaks or troughs of a wave; in the context of electromagnetic waves, such as light, it is the distance between successive crests (or troughs) of the wave

Crest - Highest point of a wave, representing the maximum displacement of the wave from its equilibrium position; peak where the wave reaches its greatest height above the baseline

ELECTROMAGNETIC SPECTRUM
Longer Wavelength Shorter Wavelength
Radio → Microwave → Infrared → VISIBLE → Ultraviolet → X-ray → Gamma Ray
Lowest Frequency Highest Frequency

Refraction - Bending of light as it passes from one medium to another with a different density; occurs because the speed of light changes when it moves through various materials.

Dispersion - Refraction which provides the seven colors of light; this phenomenon is observed when light passes through a prism.

Prism - Transparent optical element with flat and polished surfaces that disperses light

Sound - Longitudinal & mechanical wave; a wave’s motion is in the same direction as the wave, produced by vibrations; requires a medium.

Elasticity - the more elastic the more it allows sound to travel quickly

Density - the denser the object, the faster the sound

Temperature - the higher the temperature, the higher the kinetic energy, the faster the movement. The lower the temperature, the lower the kinetic energy, the slower the movement.

Sound moves faster based on densities, so in gas, sound moves slower, in solid, it is faster, and in water, it is also faster. Due to the density of the medium, the molecules are closer together which means more collisions per second, which affects the speed of sound to be faster.