Sci A 1st Quarter Notes - Science PDF

Sci A 1^st^ Quarter Laws of Motion Force -may be defined as a push or pull by one body to another. Balanced force -are forces where the effect of one force is cancelled out by another. Unbalanced force -are forces that are not equal in magnitude and may or may not act in the same direction. Ine...

Sci A 1^st^ Quarter Laws of Motion Force -may be defined as a push or pull by one body to another. Balanced force -are forces where the effect of one force is cancelled out by another. Unbalanced force -are forces that are not equal in magnitude and may or may not act in the same direction. Inertia - is the tendency of an object to maintain its initial state of motion. Newton related the concept of inertia to mass. Mass is a measure of inertia. 3 Laws of Motion 1. First Law (Inertia) - An object at rest remains at rest, and an object in motion remains in motion at constant speed and in a straight line unless acted on by an unbalanced force. 2. Second Law (Acceleration) - that the acceleration of an object is directly proportional to the net external force acting on the object and inversely proportional to the mass of the object. 3. Third Law (Action and Reaction) - for every action (force) in nature there is an equal and opposite reaction. Work, Power, Energy Work -is defined differently in physics than in everyday language. In physics, work means the use of force to move an object. Power -the rate of doing work, it is the work done in unit time. Energy -the ability to do work. TYPES OF ENERGY Kinetic energy - the energy of moving matter. Anything that is moving has kinetic energy from atoms in matter to stars in outer space. Gravitational Potential Energy - the energy an object has due to its position above Earth, energy due to its height. Elastic Potential Energy - energy stored as a result of applying a force to deform an elastic object. Chemical energy - is stored in the bonds between the atoms of compounds. Nuclear Energy - is stored in the nuclei of atoms because of the strong forces that hold the nucleus together. - Nuclei of radioactive elements such as uranium are unstable, so they break apart and release the stored energy. Potential Energy - Potential energy is the stored energy in an object due to its position, properties, and forces acting on it. Sound and Light Sound - is defined as the transfer of energy from a vibrating object in waves that travel through matter. -- is made by vibrations. Sound waves - are created by object vibrations and produce pressure waves. -- they help vibrations travel. -- sound waves are longitudinal waves 2 TYPES OF SOUNDWAVES 1. Transverse Waves - A wave in which particles move perpendicular to the direction of the wave propagation. 2. Longitudinal Waves - Travels in the small direction as the disturbance that cause it. Vibrations - a series of small fast movements that move back and forth or from side to side. Pitch - the highness or lowness of a sound. -- pitch changes when the soundwaves go faster or slower. Volume - measures the loudness or quietness of a sound - intensity is the power, the higher the intensity the louder our ears hears it. Medium (20 °C) Speed of Sound Waves (m/s) Dry Air 343 Water 1437 Wood 3850 Glass 4540 Aluminum 6320 Activities on Sound. A. 1. How is sound defined in science? \- Sound is defined as a type of energy that travels in waves. 2.) How does this definition differ the word's common meaning? \- The meaning of sound surrounds both physical and insight dimensions, which extends its usage. 3.) Hitting a drum, generates sound waves. Create a diagram to show how the sound waves begin and how they reach a person's ears. \- 4.) How do you think earplugs work? - The earplug expands until it seals the canal, blocking the sound vibrations that could reach the eardrum. 5.) What is the speed of sound in dry air at 20 °C? - The speed of sound in dry air at 20 °C is 343 m/s 6.) Why are sound waves transmitted faster in solids? - Because the molecules are closer together and more tightly bonded in solids. 7.) How does temperature affect the speed of sound in gases? - Molecules at higher temperatures have more energy and can vibrate faster and allow sound waves to travel more quickly. B.) Simulation activity 1\. Is there a difference between volume and amplitude? - Amplitude is the displacement of air molecules from their resting position. Volume is defined as either the perceived loudness of sound OR the level of a signal as it leaves the output. 2\. How do the different shapes (square, sawtooth, triangle, and sine) sound different? - The distinct shapes of sound waveforms---square, sawtooth, triangle, and sine---produce unique auditory characteristics due to their harmonic content and waveform structures.​ 3\. Why does the live input of the microphone make such jagged waveforms, while the notes produced by the computer are much smoother? - The differences in waveform appearances between live microphone input and computer-generated notes can be attributed to the nature of sound waves and the methods used to generate them. 4\. Describe the different waves for different pitches for high and low notes. - The distinct characteristics of sound waveforms that correspond to high and low pitches are primarily dictated by their frequencies and wavelengths. High-pitched sounds exhibit shorter wavelengths and higher frequencies, while low-pitched sounds possess longer wavelengths and lower frequencies, significantly influencing their auditory perception. 5\. How does pitch or frequency affect the waveform on an oscilloscope? - ​The pitch or frequency of sound significantly influences the appearance of waveforms on an oscilloscope.​ 6\. How do the curves compare for keys whose frequencies are 440 and 220 Hz? - The sound waveforms for frequencies of 440 Hz and 220 Hz exhibit notable differences in their shape and characteristics, primarily due to their differing frequencies. 7\. How do the sounds compare when the same note is played as a sine, square, or triangle waveform? - Sine waves produce a smooth and pure tone, square waves yield a rich and buzzy sound with pronounced harmonics, while triangle waves offer a brighter sound than sine waves but are less harsh than square waves. Light - defined as the electromagnetic radiation with wavelengths between 380 and 750 nm which is visible to the human eye. Wavelength - describes how long the wave is. Color - a phenomenon of light (as red, brown, pink, or gray) or visual perception that enables one to differentiate otherwise identical objects. Refraction - the bending of light rays as they pass from one medium to another, thereby changing the path of the rays. Activities on Light 1. What determines the color of visible light? - Wavelength 2. Which color of light has the longest wavelength? Which color has the shortest wavelength? - Red has the longest wavelength, at around 700 nanometers. Violet has the shortest wavelength, at around 380 nanometers 3. How does a prism separate visible light into its different colors? - A prism works because the different colors of light travel at different speeds inside the glass. 4. To a person with normal vision, a green apple appears green. Explain why. - Because the object is absorbing all the different light waves that come from a white light shining on the object except for the green light waves that are reflected back to our eyes. 5. The human eye can detect only three colors of light. What three colors are they? How can we perceive other colors of light? - These colors are blue, green, and red. But obviously, we see much more than just these three colors. 6. What are pigments? Identify the primary colors of pigments. If you combined the three primary pigment colors, what color would you get? - Primary colors of light are red, green, blue and primary pigments are cyan, magenta, yellow. When three primary colors are mixed, we get white color and when primary pigments are mixed, we get black color. 7. Sound doesn't travel through a vacuum because there are no molecules to carry it. How do we know that light does travel through a vacuum? - Electromagnetic waves, such as light waves, on the other hand do not need a medium to move through. 8. What is the range of wavelength of electromagnetic radiation the human eye can detect? - 380 to 700 nanometers. 9. What was changed in the equation v=λf in this concept? - v is changed with c 10. What color of visible light has the shortest wavelength? - Violet 11. How are we able to see objects that do not generate light? - When light falls on a non-luminous object, it is reflected by the surface towards us 12. Of what colors does white light consist? - All colors in the color spectrum. 13. Why can't sound waves be polarized? - Because they vibrate in the same direction as they travel. 14. What happens to the wavelength of light as the frequency increases? - the wavelength decreases 15. The sky appears darker when viewed through a polarizing filter. Why? - the only component of the light which is allowed to pass is the component parallel to the filter\'s plane of polarization. 16. What color will a yellow banana appear when illuminated by? - A. White light Heat and Electricity HEAT - is thermal energy transferred from a hotter system to a cooler system that are in contact. TEMPERATURE - is a measure of the average kinetic energy of the atoms or molecules of the system. Freezing is a phase of change from liquid to solid. Melting is the reverse of freezing. Condensation is the process by which water vapor changes to liquid. Evaporation is the change of liquid into water vapor. Sublimation involves a change of phase from solid to gas. Deposition is when a substance goes from gas to solid. HEAT INDEX The heat index, also known as the apparent temperature, is what the temperature feels like to the human body when relative humidity is combined with the air temperature. Combustion - is a chemical process in which a substance reacts rapidly with oxygen and gives off heat. 5 TYPES OF COMBUSTION 1. Rapid combustion - The process in which large amount of heat and light are released in a very short span of time. 2. Explosion - Is when a sudden reaction takes place with the release of heat and light and with large amounts of gases. 3. Spontaneous combustion - It is the outbreak of fire without heat from an external source. - Typically, through heat generated internally by rapid oxidation. 4. Complete combustion - It takes place when there is a sufficient amount of oxygen and it produces no smoke. 5. Incomplete combustion - It takes place when there is insufficient amount of oxygen supply. Flame - it is the visible part of a fire - a result of an exothermic reaction - gives heat and light The temperature and color of a flame depends on what type of fuel is used to produce the fire. ZONES OF A CANDLE FLAME The outer (non-luminous) zone (Blue) -- Hottest part The middle (Luminous) zone (Yellow) -- Moderately hot The inner (Dark) zone (Black) -Least hot Electricity - is the flow of energy that can be used to power devices, typically carried by electrons, through a conductor. - a form of energy that can be used to power devices and machines. -- is generated by chemical reactions, mechanical energy, or solar energy. -- can be transformed into other forms of energy such as heat, light, or mechanical energy. Electric Current - the rate at which electric charge flows through a conductor, such as a wire. -- it is measured in amperes (A). When a voltage is applied across a conductor, it pushes the electrons to move, creating a flow of charge. This flow of charge constitutes the electric current, and it can be either direct (DC) where the current flows in one direction or alternating (AC) where the current changes direction periodically. Conductor - a material that allows electric current to flow easily due to the presence of free electrons. These free electrons can move throughout the material, carrying electric charge. Metals like copper, aluminum, and silver are good conductors.  Electricity flows differently through various materials due to their atomic structure and the availability of free electrons. Conductors have atoms with loosely bound electrons in their outer shells. These electrons can move freely when an electric field is applied, creating a flow of electric current. Insulators have tightly bound electrons that are not free to move. This means electric current cannot flow easily through these materials. Semiconductors have properties between those of conductors and insulators. At room temperature, they have few free electrons, so their conductivity is low. However, by adding impurities (a process called doping) or by increasing temperature, the number of free electrons can increase, allowing electricity to flow under certain conditions. OHM'S LAW: CURRENT, VOLTAGE, AND RESISTANCE Voltage (V): This is the driving force or potential difference that pushes electric charges through a circuit. Current (I): The flow of electric charge through a conductor. The higher the current, the more charge is flowing per unit of time Resistance (R): the opposition to the flow of current in a circuit. Higher resistance means its harder for the current to flow. OHM'S LAW RELATIONSHIPS If voltage increases while resistance remains constant, the current increases. If resistance increases while voltage remain constant, the current decreases. If current increases and the voltage remains the same, the resistance must decrease. IN A PRACTICAL SENSE: A circuit with higher voltage will push more current, assuming the resistance doesn't change. If the resistance increases, the current will decrease for the same voltage. SERIES AND PARALLEL CIRCUITS Series Circuit - has only one loop through which current can flow. -- if the circuit is interrupted at any point in the loop, no current can flow through the circuit and no devices in the circuit will work. Parallel Circuit - has two or more loops through which current can flow. -- if the circuit is interrupted in one of the loops, current can still flow through the other loop(s). SERIES CIRCUITS CONNECTION: Components are connected one after the other in a single path. CURRENT: The same current flows through all components VOLTAGE: The total voltage of the power source is divided among the components. Each component gets a friction of the total voltage depending on its resistance. RESISTANCE: The total resistance is the sum of the resistance of all components. More components increase the total resistance. EFFECT OF FAILURE: If one component fails, the entire circuit is broken, and the current stops flowing ADVANTAGES: 1.) Series circuits are easier to design and require fewer wires, making them simple and cost-effective. 2.) Since the current is the same throughout the circuit, it can be easier to calculate the overall power usage. PARALLEL CIRCUITS CONNECTION: Components are connected in separate branches, each forming its own path to the power source. CURRENT: The total current is divided among the branches. Each branch gets a different current depending on its resistance. VOLTAGE: The voltage across each branch is the same as the total voltage of the power source. RESISTANCE: The total resistance decreases as more branches are added because the current has more paths to take. EFFECT OF FAILURE: If one component fails in a branch, the other branches continue to work, as current can still flow through the remaining paths. ADVANTAGES: 1. Each component operates independently. If one component fails, the others will still work, making it more reliable for practical applications. 2. Each component gets the same voltage as the power source, so all devices operate at full capacity, which is essential for consistent performance. 3. Adding more branches decreases the total resistance, allowing, more current to flow with less resistance. - A short circuit occurs when electrical current deviates from its intended path due to unintended connections or insulation failures. This deviation can result in a surge of current that poses significant risks, including fires and electrical shocks. ELECTRIC SAFETY FEATURES - Safety features are built into electric circuits and devices. They include three-prong plugs, circuit breakers, and GFCI outlets. HOW TO USE ELECTRICITY SAFELY - Never mix electricity and water because water is a very good electric conductor. - Never plug in devices with wet hands because the current could flow through the water and you. - Avoid plugging in many devices into one outlet at the same time. They could overheat and start a fire. - Never use devices with damaged cords or plugs. They can cause shocks, shorts, and fires - Never put anything except plugs into outlets as this can cause a serious shock that can be fatal. - Never go near fallen electrics line that could be carrying a lot of current. Report fallen lines to the electric company as soon as possible. FORMULAS: Work = Distance x Force Kenetic Energy (KE) = ½ mass x velocity\*2 Force = Work/Distance Potential Energy (Gravitational) = weight x height (mgh) Distance = Work/Force Q = C x M x ∆T Power = Work/Time (V=IR) (R = V/I) (I = V/R) °C = (°F - 32) × 5/9 Centripetal force = fc= mv\*2/r °F = °C × (9/5) + 32 Average Velocity = u + u/2 UNITS: W -- KE - PE = J(Joules) F - Fc = N(Newton) V -- A = m/s (a=m/s\*2) P = Watt M = kg S -- D -- H = m F = force (Newton/N) P= power (watts/w) M= mass (kg) W= work (J/Joules) A = acceleration (m/s\*2) H = Height (m) D= Distance/Displacement (m) KE = Kinetic energy (J/Joules) PE = Potential Energy (J/Joules) NOTE: I MOSTLY RESEARCHED ALL THE TOPIC IM NOT REALLY SURE IF THEY ARE CORRECT OR NOT. (CREDITS TO LIANE OPOLINTO SA FORMULAS) Good luck sa pag review and especially good luck sa exam! Stay safe always and god bless!