Science 10 2nd Grading PDF

SCIENCE MIRRORS AND LENSES Definition of Terms Optics - the branch of physics that studies how light behaves, including how it travels, bends, reflects, and interacts with objects. It explains how we see things and how devices like lenses, mirrors, and glasses work. Refraction...

SCIENCE MIRRORS AND LENSES Definition of Terms Optics - the branch of physics that studies how light behaves, including how it travels, bends, reflects, and interacts with objects. It explains how we see things and how devices like lenses, mirrors, and glasses work. Refraction - the bending of light as it posses from one medium to another (like from air to water), due to a change in its speed. This is why objects underwater appear bent or shifted from their actual position. Reflection - is when light bounces off a surface, like when you see your image in a mirror. The light rays hit the surface and are redirected back without passing through the material. Real Image - is formed when light rays actually meet in front of a mirror or lens. It can be projected onto a screen and usually appears upside down. Virtual Image - A virtual image only appears to come from behind a mirror or lens. It is formed by light rays that don’t actually meet, cannot be projected onto a screen, and is upright (same orientation as the object). MIRROR - is any surface (usually glass covered with metal film) that can reflect light without any diffusion to form an image of the object in front of it. Three Different Types of Mirror: 1. Plane Mirror is a mirror with a flat reflective surface forms an image same size of the object also forms left-right reversed images produces an upright image produces a virtual image the location of the image formed in a plane mirror is the same as the distance of the object 2. CURVE MIRRORS OBJECT’S LOCATION CONCAVE MIRROR CONVEX MIRROR (description) - bulging inward - bulging outward - image formed is - the image formed is dependent on the object’s independent of the location object’s position - the image formed is always reduced in size, is upright, and virtual - as the object moves closer to the mirror, the image on the virtual side increases in size but remains smaller than the object - the image also moves closer to the mirror as well Beyond the center - the image formed is reduced in size, inverted, and real At the center - the image formed has the same size of the object, is inverted, and is real Between the center and the - the image formed is focus magnified, inverted, and real At the focus - no image will be formed In front of the focus - the image will be magnified, upright, and virtual (examples) headlights, flashlights, makeup mirrors, telescope mirrors, shaving mirrors, and dental mirrors LENSES - a lens is a transparent material that refracts light to produce image OBJECT’S LOCATION CONVERGING LENS DIVERGING LENS Beyond 2F - the image formed is - the image formed has the located somewhere in same characteristics between F and 2F regardless of the object’s - the image would be location reduced in size, inverted, - The image is ALWAYS and real reduced in size, upright, and virtual - the image is always formed at the side where the object is located - as the object gets closer to the mirror, the image on the virtual side gets closer to the lens as well, and the size pf the image increases as well At 2F - the image formed on the other side will be located at 2F as well, still reduced in size, inverted, and real Between 2F and F - the image is located beyond 2F on the other side - it is now magnified, inverted, and real At F - no image will be formed chat In front of F - the image formed is located between F and 2F on the same side of the lens - image formed is magnified, upright, and virtual REPRODUCTIVE SYSTEM - Is an organ system responsible for producing offspring - Involves several key processes and components in both males and females - In females: The system includes the ovaries, which produce ova (eggs), and the fallopian tubes, where fertilization by sperm occurs. The fertilized egg then travels to the uterus for implantation and development during pregnancy The Male Reproductive System Role - Key role is to produce sperm cells in the testes and release them inside a female - If a sperm cell successfully reaches an egg cell and fertilization occurs, an embryo will be formed - The embryo will develop into a baby over the course of a pregnancy - The male reproductive system is controlled by hormones The Menstrual Cycle and Hormones - Hormones play a crucial role in regulating the reproductive system - In females: Estrogens and progestins regulate the menstrual cycle and prepare the uterus for pregnancy - In males: Androgens like testosterone are responsible for the development of male characteristics and sperm production - When an ovum is unfertilized, the uterus lining sheds and leads to a hemorrhage, called menstruation. In a life cycle, a woman’s body is vulnerable to a variety of changes. The cycle of these changes occur in women every month, positively for pregnancy is called the menstrual cycle Estrogen - A female sex hormone made in the ovaries - Responsible for puberty in girls and regulating the menstrual cycle - Stops FSH being produced to prevent more than one egg being released each cycle, it repairs and thickens the uterus lining and stimulates the pituaitary gland to release LH Pituitary Gland - Where FSH and LH are produced Ovaries - Produce estrogen and progesterone Placenta - If a woman became pregnant, this produces progesterone to maintain the lining of the uterus and to stop menstruation The Phases of The Menstrual Cycle 1. Menstrual Phase (Day 1-5) - This is the phase when the uterine lining (endometrium) sheds and is expelled from the body as menstrual flow - Hormones: Estrogen and progesterone levels are low 2. Postmenstrual Phase / Follicular Phase (Days 6-13) - After the menstrual flow stops, the endometrium begins to thicken and rebuild in preparation for a possible pregnancy - Hormones: Estrogen levels gradually increase, stimulating the growth of follicles in the ovary 3. Ovulation (Day 14) - A mature egg is released from the ovary and travels through the fallopian tube - Hormones: A surge in luteinizing hormone (LH) triggers ovulation 4. Premenstrual Phase / Luteal Phase(Days 15-28) - The empty follicle after ovulation transforms into the corpus luteum, which produces progesterone  - Hormones: Progesterone helps to maintain the thickened uterine lining in preparation for a fertilized egg. If no fertilization occurs, the corpus luteum degenerates, and progesterone levels fall Menstrual Disorders 1. Dysmenorrhea - Is characterized by severe pain during menstruation 2. Amenorrhea - Is the abnormal absence of menstruation 3. Oligomenorrhea - Is the abnormal and infrequent menstrual period Role of Hormones in our Reproductive System - Crucial during puberty, ovulation, pregnancy, and development - Controlled by the pituitary gland, which is regulated by the hypothalamus Hormones - Chemical messengers that regulate body functions or specific organs - Released by endocrine glands - Carried through the bloodstream to target organs Reproductive Glands Activity - Low levels of activity until age 10 - Hormone levels increase after age 10, leading to physical changes Hypothalamus and Pituitary Gland - Hypothalamus releases chemical signals to the pituitary gland - Pituitary gland produces follicle-stimulating hormone (FSH) and luteinizing hormone (LH) GLAND HORMONES FUNCTION Testes (Male) Testosterone It regulates the development of the male sex organs while still in an embryo. It also controls sex drive and secondary sex characteristics at puberty Ovaries (Female Estrogen It controls sex drive and regulates the development of female secondary sex characteristics at puberty Progesterone It controls the development of the endometrium )mucus membrane lining the womb) during the menstrual cycle and the maintenance of the uterus during pregnancy Prolactin Stimulates the production of milk in the mammary glands Pituitary Luteinizing Hormone In females, it stimulates ovulation, maturation of egg (LH) cells, and progesterone production In males, it stimulates sperm and testosterone production Follicle-stimulating In females, it stimulates the maturation of egg cells in hormone (FSH) the ovary and estrogen production In males, it stimulates sperm production ENDOCRINE SYSTEM - Includes glands that release hormones into the bloodstream, regulating daily activities and overall development, including functions of the ovaries and testes - Works like a thermostat, turning on and off in response to hormone levels in the body, similar to how a thermostat adjusts based on temperature - When it malfunctions, it can affect energy levels, physical appearance, and reproductive ability Hormones - Chemical messengers produced by glands in the endocrine system that travel through the bloodstream to regulate various bodily functions, such as growth, metabolism, mood, and reproduction, helping to maintain homeostasis - Regulates the organs through chemical signals. It controls glands by sending signals that prompt a response, ensuring a balance of chemicals Major Glands in the Endocrine System and Their Hormones GLAND HORMONE FUNCTION AND LOCATION Hypothalamus Releasing factors Location: Beneath the thalamus, Oxytocin Antidiuretic in the brain. hormone (ADH) Located at the base of the brain. Function: Regulates the endocrine system by controlling the pituitary gland; maintains homeostasis by influencing hunger, thirst, sleep, and body temperature Pituitary Gland Adrenocorticotropic Location: Still at the base of the hormone (ACTH) Thyroid brain, below the hypothalamus stimulating hormone (TSH) Growth hormone Function: Often referred to as prolactin the “master gland,” it regulates other endocrine glands and controls growth, metabolism, and reproductive functions by releasing various hormones Pineal Gland Location: Deep in the center of the brain, between the two hemispheres Function: Regulates sleep-wake cycles by producing melatonin, a hormone that signals the body when it’s time to sleep It plays a crucial role in maintaining circadian rhythms, which are the natural body cycles of sleep and wakefulness Thyroid Gland Thyroxine Calcitonin Location: In the front of the neck, below the adam’s apple or voice box Function: Produces hormones (thyroxine and triiodothyronine) that regulate metabolism, energy levels, and growth Parathyroid Glands Parathyroid hormone Location: Four small glands located behind the thyroid gland in the neck Function: Regulate calcium levels in the blood by releasing parathyroid hormone (PTH) and phosphorus in the bloodstream Thymus Estrogen Progesterone Location: In the upper chest, Testosterone behind the sternum or breastbone Function: Plays a role in the immune system by producing thymosin, which stimulates the development of T-cells (a white blood cell to protect the body from infection and cancer) Pancreas Insulin Location: Behind/beneath the Glucogen stomach, in the upper abdomen Function: Produces insulin and glucagon, which regulate blood sugar levels, as well as digestive enzymes Adrenal Glands Adrenaline (epinephrine) Location: On top of each kidney Aldosterone Function: Produce hormones like adrenaline (epinephrine) and cortisol, which helps our fight or flight response, regulate metabolism, immune response, and stress reactions  Ovaries Estrogen Progesterone Location: In the lower abdomen, Testosterone on both sides of the uterus (in females) Functions: Produce estrogen and progesterone, which regulate the menstrual cycle, reproductive functions, and secondary sexual characteristics Testes Estrogen Progesterone Location: In the scrotum (in Testosterone males) Function: Produce testosterone, which influences male sexual development, sperm production, and secondary sexual characteristics (idk if these are hormones???) Medical Conditions 1. Diabetes - This endocrine disorder affects the way your body uses the energy from the food you eat. Diabetes develops when the pancreas doesn’t make enough of a hormone called insulin, or insulin doesn’t work as it should 2. Ovarian Cyst - Fluid-filled sacs on the ovaries that can cause pain, irregular periods, and hormonal imbalances 3. Growth Hormone Deficiency - Insufficient production of growth hormone by the pituitary gland, leading to stunted growth in children and various metabolic issues in adults NERVOUS SYSTEM - The complex network of nerves in the body ○ Central Nervous System ○ Peripheral Nervous System ★ Central Nervous System (CNS) - Consists of the brain and spinal chord - Serves as the main control center for processing and integrating sensory information, coordinating responses, and managing higher functions such as thinking, emotions, and memory - Receives signals from the body, interprets them, and sends out instructions to execute actions 1. Brain - Control center of the body - Processes information, controls thoughts and emotions, and helps coordinate movements 2. Spinal Chord - Connects the brain to the rest of the body - Sends signals between the brain and body and helps control reflexes (like pulling your hand from something hot) ★ Peripheral Nervous System (PNS) - Includes all the nerves that lie outside the CNS - Connects the CNS to the limbs and organs, allowing communication between the brain and the rest of the body 1. Somatic Nervous System - Controls voluntary movements and relays sensory information to the CNS 2. Autonomic Nervous System - Regulates involuntary functions such as heart rate, digestion, and respiratory rate Neurons - The main cells that send and receive messages in the nervous system 1. Dendrites - receive signals from other neurons 2. Cell Body - Processes these signals 3. Axon - Sends signals to other neurons or muscles Feedback Systems - Many body functions operate using these to maintain a stable internal environment, known as Homeostasis - This control system constantly monitors and adjusts various conditions in the body, such as PH levels, temperature, and the amounts of necessary substances, ensuring they remain relatively constant for normal cell function Internal Control System - Quickly responds to changes in its conditions 1. Sensors - Specialized cells or nerve endings that detect changes in the internal or external environment, such as temperature, pain, light, or pressure - Part of the PNS and they relay information to the CNS 2. Control Center - Processes the information received from the sensors and decides on the appropriate response  - Typically done in the brain or the spinal chord, both of which are part of the CNS 3. Communicating System - The nervous system transmits the decision made by the control center to the rest of the body - Involves motor neurons carrying the signal from the brain or spinal chord to the relevant body parts 4. Targets - These are the organs, muscles, or glands that carry out the response - Once they receive the signal from the control center via the communicating system, they act to bring out a change MOTORS AND GENERATORS Magnetism The force exerted by magnets when they attract or repel each other Ex. Lodestone - has a property of attracting iron particles to it, naturally magnetized piece of the mineral magnetite Electro Magnetic Induction When current flows through a wire held in a magnetic field, a force is created that moves the wire The opposite is also possible: if a wire is moved across a magnetic field, a current is produced, called electromagnetic induction Induction also occurs if a magnet is moved in a coil of wire, or if a coil of wire rotates in a magnetic field In all these methods of inducing a current, the wire and magnetic field move perpendicular to each other. If they move parallel to each other, no current is induced. Generators Transforming mechanical energy into electrical energy, often using mechanical movement (like turbines) to produce electricity Working Principle of Generators They work on the principle of electromagnetic induction When a conductor, such as a coil of wire, moves through a magnetic field, it induces an electromagnetic force (EMF) in the conductor. This process converts mechanical energy into electrical energy. Parts and Functions of Generators 1. Brushes - Conductive materials that maintain electrical contact with the rotating commutator, allowing current to flow to the windings 2. Terminals - Connection points for the power supply, facilitating the flow of electricity into the motor 3. Commutator - A rotary switch that reverses the current direction in the armature windings, ensuring the output current is direct (DC) 4. Sealed Ball Bearing - Reduces friction between moving parts, allowing the shaft and armature to rotate smoothly 5. Shaft - The central component that transfers mechanical energy to the armature and connects it to the driving source (like an engine) 6. Frame or Yoke - The outer structure that supports and houses the internal components, providing rigidity and stability  7. Pole Shoe - A magnetic component that helps in directing the magnetic field produced by the field windings, enhancing the generator’s efficiency 8. Field Windings - Coils of wire that create a magnetic field when an electric current flows through them. This field interacts with the armature to generate electricity Energy Conversion: Generator 1. Prime Mover - This could be a turbine, engine, or any mechanical device that provides the initial mechanical energy to drive the generator. 2. Mechanical Energy - The mechanical energy produced by the prime mover is transferred to the rotor. 3. Rotor (Armature) - The rotating part of the generator that converts mechanical energy into electrical energy through electromagnetic induction. 4. Stator - The stationary part of the generator that contains coils of wire. When the rotor moves, it induces a voltage in the stator. 5. Electrical Output - The generated electrical energy is then sent out to be used by external circuits or stored in batteries. Examples of Generators: Backup Power Systems ○ Providing electricity during outages using portable generators Power Plants ○ Converting mechanical energy (from turbines) into electrical energy for the grid Renewable Energy ○ Wind turbines and hydroelectric plants harness natural energy sources Electric Motors Converts electrical energy into mechanical energy through electromagnetic principles, enabling motion in various applications, from household appliances to industrial machinery Working Principle of Electric Motors Operate on the principle of electromagnetism, specifically the Lorentz force When an electric current passes through a coil of wire within a magnetic field, it generates a force that causes the coil to rotate. This rotation is converted into mechanical energy, which can perform work Lorentz force experienced on a charged particle due to electric and magnetic fields Parts and Functions of Electric Motors 1. Stator - The stationary part that generates a magnetic field, typically made up of permanent magnets or electromagnets 2. Windings - Coils of wire wrapped around the rotor or stator, which create magnetic fields when current flows through them  3. Brushes - Conductive materials that maintain electrical contact with the rotating commutator, allowing current to flow to the windings 4. Terminals - Connection points for the power supply, facilitating the flow of electricity into the motor 5. Commutator - A rotating switch that reverses the direction of current in the windings, ensuring continuous rotation of the armature 6. Armature - The rotating part of the motor, usually consisting of the windings and iron core, which interacts with the magnetic field to produce motion Energy Flow: Electric Motor 1. Power Source - Provides electrical energy to the motor 2. Controller - Regulates the input power and manages motor operations. Motor Driver: Converts control signals into higher currents or voltages to power the motor 3. Stator - Stationary part of the motor containing coils that generate a rotating magnetic field 4. Rotor - Rotating part of the motor that is acted upon by the magnetic field to produce motion 5. Mechanical Load - The component or system that the motor is driving, converting electrical energy into mechanical work Examples of Electric Motors Household Appliances ○ Fans ○ Refrigerator ○ Washing machines Transpotation ○ Electric vehicles ○ Trains ○ Drones Industrial Machinery ○ Converyer belts ○ Pumps ○ Fans