science

• Motion: is the continuous change in position with respect to a fixed point or relative to a reference point.
• Distance : (scalar quantity) length of a path traveled by an object
• Displacement: (vector quantity) is change in position of an object with respect to its initial position. It is the straight distance from the initial position to the final position. It is the distance between starting and final position of an object. (It's vector bc it specifies both magnitude and direction)
• dy = N and S (add if needed)
• dx = E and W (add if needed)
• Total distance: d1 + d2 + d3
• Uniform motion: an object moving with a constant speed and direction
• Instantaneous speed: The rate at which an object moves at any given instant. The smaller the time interval, the more accurate your measurement of speed. (how fast an object is moving at the particular moment)
• Speedometer: device fixed on a vehicle's cockpit and is used to measure the car’s actual traveling speed. The speedometer in every car has an odometer that records the distance traveled.
• Vector quantity: requires magnitude and direction for a complete description (i.e displacement, velocity, acceleration, force, momentum and impulses)
• Scalar quantity: Do not require direction and can be described by magnitude only (numerical value) (i.e distance, time, mass, temperature, area, volume, density  and speed)
• Speed (scalar quantity): a change in distance within a given time interval. Basically how fast something is going. Speed, therefore, is the rate of change in position. It can be measured by dividing the distance covered by the elapsed time. 

  S = d / t
• Velocity (vector quantity): the direction an object is moving and how fast something is moving in a certain direction. It  is a speed with direction. When you describe an object’s rate and direction of motion, you are describing its velocity
• Acceleration (vector quantity): measure of how quickly the speed or velocity of an object changes.
• Centripetal acceleration: the acceleration of a body traversing a circular path. ex. when you swing a ball on a string in a circle
• Deceleration: slowing down

  Acceleration: speeding up
• Speed: how fast a body is moving in a given direction
• Waves: : disturbances that carry energy through matter or space
• Waves travel forward as the water moves up or down. It is not the water that moves forward, but only the waves. When a wave passes a point in the water, the water molecules collide with other water molecules causing the water to move up and down. These series of collisions carry the energy through the water
• Medium: any kind of matter through a wave can travel
• Vibration: back-and-forth or up-and-down movement of an object. A vibrating object is moving and any moving object has energy. A vibrating object transfers some of its energy to the surrounding particles causing them to vibrate as well. These particles give off energy to the particles near them and so on.
• Mechanical waves: waves that require a medium for their transmission. Ex. when you talk, the vocal cords in your throat vibrate and create a sound that eventually travels through the air and reaches your ears. Sound energy makes your eardrums vibrate. If you hit the surface of a drum with a stick, the surface of the drum starts to vibrate creating its characteristic sound.
• Electromagnetic waves:  waves that can travel without a medium. Unlike sound, light can travel through an empty space or a vacuum. The energy of the sun reaches us even if the sun is so far away because light does not need a medium to be transmitted.
• Transverse waves: in this wave, the particles of the medium move back and forth perpendicular to the direction of the waves. Water waves are also transverse ways. As the waves travel forward, the particles of the medium move up and down perpendicular to the waves direction.
• Crests: highest points of a transverse wave
• Troughs: lowest point of a transverse wave
• Longitudinal waves:  when you stretch out a spring toy and push and pull at one end, you can produce longitudinal waves. The spring moves forward and backward in the same direction that the wave travels. You give energy to the spring causing it to move back and forth. Notice that some parts of the spring have coils that are close together while in other parts, the coils are spread out. 
• Compression: coils are close together in a longitudinal wave
• Rarefactions: coils are spread out in a longitudinal wave
• In longitudinal waves, the motion of the medium is parallel to the direction of the wave’s motion.
• Sound: something we hear with our ears
• Vibrations: back-and-forth motions that create sound
• Sound wave: produced when an object vibrates rapidly in a medium like air
• Compression region: formed by the vibrating object moving forward and pushing the air around it and compressing it. 
• Rarefaction: formed by the object moving backward and creating a region of low pressure
• Light: a form of energy that helps us see things. It comes from sources such as the sun, light bulbs, or flashlights. When light travels, it moves in a straight line called a “ray”.
• Electromagnetic radiation: a special type of energy that travels in waves through space. It’s like a wave of energy that can move without needing anything else to carry it. 
• Visible light spectrum: part of electromagnetic radiation that allows us to see things.
• Visible light: type of electromagnetic radiation that allows us to see the world around us.
• Color: way our eyes perceive different wavelengths of light. It’s what makes objects look different from one another. When light shines on an object, some of the light is absorbed, and some is reflected back to our eyes. The colors we see are the result of the reflected light.