2nd Quarter Science Reviewer PDF

2nd Quarter Science Reviewer 2. Trough - Lowest part, as low as the Types of Tests: wave goes Test I. Multiple Choice (35 Pts.) 3. Amplitude - Vertical distance between Test II. Identification ( 10 Pts.)...

2nd Quarter Science Reviewer 2. Trough - Lowest part, as low as the Types of Tests: wave goes Test I. Multiple Choice (35 Pts.) 3. Amplitude - Vertical distance between Test II. Identification ( 10 Pts.) trough and center line or peak and the EM Waves & Uses center line. Reflection & Mirrors 4. Wavelength - Distance from two similar Refraction parts of a wave. Test III. Ray Diagramming (15 Pts.) Longitudinal Waves Plane & Conver Mirrors - Waves vibrating in the direction of propagation (the way a wave travels) Test IV. Problem Solving (10 Pts.) Snell’s Law Parts of a LONGITUDINAL WAVE: Lesson 1: Electromagnetic Waves and Uses 1. Compression - a region where particles are closest together. 2. Rarefaction - a region where particles are furthest apart. Electromagnetic Waves - Do not require a medium and consist of Mechanical Waves oscillating electric and magnetic fields. - Travel only through matter (solid, These waves are transverse, meaning liquid, gas) they move perpendicular to energy - When these media are disturbed transfer. repeatedly, waves are propagated. - Electromagnetic waves travel at the speed of light (300,000 km/s in a Types of Mechanical Waves: vacuum). Transverse & Longitudinal - They slow down in denser media (fastest in gases, slowest in solids). Parts of a TRANSVERSE WAVE: - Frequency refers to the number of waves passing a point per second. - One complete cycle is a Period Electromagnetic Spectrum - EM waves are arranged based on frequency and wavelength (low to high) 1. Crest (Peak) - Highest part, as high as the wave goes.  Wave Front - an imaginary surface representing corresponding wave points that vibrate in unison. Incident Light: Light that strikes a surface. Reflected Light: Light that bounces off a surface. Types of Waves in the Spectrum: Normal Line: A line perpendicular to the surface where light is reflected. ➔ Radio Waves: Used for TV and radio signals. LAW OF REFLECTION ➔ Microwaves: Common in satellite The angle of incidence equals the angle of communications, radar, and mobile reflection. phones. ➔ Infrared: Perceived as heat, used in remote controls and thermal imaging. ➔ Visible Light: Enables sight; includes all colors of the rainbow. ➔ Ultraviolet: Found in sunlight, absorbed by the skin; can cause normal cells to become cancerous. ➔ X-rays: Pass through skin and tissue but not bones or metal; used in medical imaging and industry to check for cracks Types of Reflection or other damage. Diffuse Reflection - Scattered reflection off ➔ Gamma Rays: High-frequency waves rough surfaces. used in cancer treatment and sterilization. Specular Reflection - Mirror-like reflection off smooth surfaces. Lesson 2: Reflection and Mirrors Optics - The study of light, its behavior, and interactions with matter. Nature of light - Light has wave-particle duality, acting as both a wave and a particle. Einstein “Light is a particle” Christiaan Huygens “Light is a wave” Mirrors and Types Ray - an idealized model of light propagation in Plane Mirrors - Flat mirrors that create images a specific direction. of the same size, orientation, and distance from the mirror Spherical Mirrors: Spherical Mirrors - It is a second class of Concave - Curves inward; can create mirror in the form of a slice of real or virtual images depending on a spherical surface. object position These are called spherical because if Convex - Curves outward; always you take a sphere and cut it then polish produces virtual, upright, and reduced the inside of one and the outside of the images other, you will get a concave mirror and a convex mirror. Ray Diagrams - Used to trace the path of light and locate image positions. Rules for Ray Diagramming in Spherical Mirrors Descriptions of Image SIZE (larger, same, smaller) Concave Mirrors: ORIENTATION (upright, inverted) ○ Rays through the focal point POSITION (real, virtual) reflect parallel to the principal Real - image is infront of mirror (in front) axis. Virtual - images behind of mirror (behind) ○ Rays parallel to the principal axis reflect through the focal LAW OF PLANE MIRRORS point. The image is always the same distance behind ○ Rays through the center reflect the mirror as the object is in front of the mirror. back on themselves.  Convex Mirrors: Rays reflect in a way that they appear to diverge from the focal point on the opposite side. Lesson 3: Refraction When light travels through different media, it changes its velocity and produces different images through refraction. Refraction - bending of light waves as they enter or cross the boundary between two media LAWS OF REFRACTION with different densities. I. The incident ray, refracted ray, and the normal line at the point of incidence all lie on the same plane. How does refraction occur? Light refracts towards the normal line when moving from a less dense to a more dense medium (slowing down) Light refracts away from the normal line when moving from a more dense to less dense medium (speeding up) Snell’s Law - The law of refraction was first Optical Phenomena observed by Willebrord Snellius (Snell), a Dutch physicist, as he described the relationship Mirages: Created when light refracts through of the angle of incidence to the angle of layers of air at different temperatures. refraction Formula: n1sin⁡θ1=n2sin⁡θ2​, where n represents the index of refraction. The speed of light in the material/medium is inversely proportional to its index of refraction. The higher the index of refraction, the slower the velocity of light. As a result, the light will bend toward the normal Rainbows: Result from refraction and line, because it is moving slowly. dispersion of light in water droplets. If the index of refraction of the material is smaller, then the velocity of light is faster. As a result, the light tends to move away from the normal line. Camera Lenses and Eyeglasses: Utilize refraction to focus and correct vision.