Science Notes PDF

SCIENCE L10 Ray Tracing - Method used in optics to determine how light behaves when it interacts with lenses or mirrors. Thin lenses - Bends light at a single plane and has 2 focal points, one on each side of lens. are commonly used in ray tacing because they simplify calculations. - Widel...

SCIENCE L10 Ray Tracing - Method used in optics to determine how light behaves when it interacts with lenses or mirrors. Thin lenses - Bends light at a single plane and has 2 focal points, one on each side of lens. are commonly used in ray tacing because they simplify calculations. - Widely used to form clear images in optical systems. - Camera, Light enter thin lens, it focuses on film or sensor to make sharp photo. Key rules 1. Ray entering a converging lens parallel to axis passes through its focal point on the other side. - Converging lenses, such as convex lenses, bend light rays towards a single point called focal point. - Magnify glass focus on a point to magnify stuff. 2. Ray entering a diverging lens parallel to axis appears to come from its focal point. - Diverging lenses like concave lenses, spread out lights as thought they came from focal point. - Eyeglass for near-sighted people, it adjust how light enter eye. 3. Ray passing through center of any lens dont bend. - Center of lens, curvature is minimal so light continue in straight line. - Camera, light pass through lens center contribute to focused image. 4. Ray entering a converging lens through its focal point exits parallel to its axis. - When light pass through focal point, lens bends parallel to its principal axis - Projectors, to spread light evenly accross screen. 5. Ray heading toward the focal point of diverging lens exits parallel to its axis - Diverging lenses redirect light approaching the focal point to emerge as parallel rays. - Peepholes, uses diverging lenses to show wider view. Types of images 1. Real images - formed when light rays actually converge at a point. Can be captured on physical surfaces like screens/film. ~ Movie projectors make real images on large screens. 2. Virtual images - formed when light rays dont physically meet but appear to diverge from common point. This cant be projected onto screen ~ Mirrors, images of your reflection, make object appear in mirror. Applications of ray tracing 1. Camera - By predicting how lenses focus light, ray tracing allows camera designers to ensure sharp, clear, photos. 2. Binoculars - Ray tracing helps calculate how lenses magnify distant objects. 3. Eyeglasses - Ray tracing is used to design corrective lenses that adjusts light. 4. Projectors - These rely on ray tracing to focus and project images on screens. L11 Electric Motors - Electrical energy into mechanical energy using loops of wire within a magnetic field. - Interaction between the magnetic field and the current creates a force (Lorentz Force) that makes wire spin. Ex: Fans, Elevator, Electric cars Electric Generators - The Principle Electromagnetic Induction makes Mechanical energy into Electrical energy. - Spinning coil of wire within magnetic fields generates electric current. Ex: Hydropwer plant, Wind Turbines, Steam Power Stations Transformers - Adjusts the voltage of electricity for efficient transmission and safe use. - Uses Electromagnetic Induction between 2 coils of wire, Primary (input) and Secondary (output) Ex: Phone charger, Power grids, Appliances Magnetism and Electricity with Applications ~ Properties of magnet - Magnets have north and south poles. Opposite attracts, Like poles repel. Cutting it makes smaller magnet w both poles. Ex: Compasses, Magnetic Levitation Trains, Recycling, Medical Imaging (MRI) L12 General Over View Hormones - From pituitary gland, adrenal cortex, and gonads regulate reproduction.  - Hypothalamus initiates this by releasing GNRH, this signals production of fsh and Lh regulating gamete and hormone production. Hypothalamus - Helps manage your body temp, hunger, thirst, mood, sex drive, blood pressure. Pituitary Gland - Growth metabolism and reproduction. (Brain) Adrenal Cortex - Produces hormones that controls sex, salt, sugar balance. (kidney) Gonads (Ovaries & Testes) - Involved reproduction - GnRH - (Gonadotroph) - Releasing hormones - FSH - Follicle - stimulative hormone - LH (Luteinizing hormone) Male Reproductive System - FSH promotes sperm maturation. LH stimulates testosterone reproduction, sperm creation, and male traits like deep voice, muscle growth. Female Reproductive System - FSH helps develop egg cells. LH triggers ovulation. Estradiol and Progesterone regulate the menstraul cycle, prepare for pregnancy, and female traits like breast growth. Hormones in Pregnancy and Lactation Prolactin - Stimulates milk production Oxytocin - Causes uterine contractors during childbirth and milk ejection during breast feeding. Pitocin - Synthetic oxytocin, used to induce labor in hospitals. L13 Phases of menstrual system 1. Mentrual Phase - Shedding of uterine lining when pregnancy doesnt occur. 2. Proliferative Phase - Estrogen Rebuilds the uterine lining. 3. Ovulatory Phase - LH surge triggers egg release. 4. Secretory Phase - Projesterone stabilizes the uterine lining for possible pregnancy. Ex: Tracking these phases helps in planning or avoiding pregnancy through natural planning methods. Feedback Mechanism Negative Feedback - Prevents hormone overproduction, maintaining balance. Ex: High testosterone signals the hypothalamus to reduce GnRH controlling hormone levels in men. Positive Feedback - Temporarily increases hormone production, maintaing balance. Ex: Fertility treatments may mimic this surge to stimulate ovulation. During Pregnancy - hCG (Human Chrionic Gonadotropin) - Support the corpus luteum to sustain pregnancy. - Prolactin - Prepares for breastfeeding, and oxytocin assists during childbirth. Ex: Pregnancy test detect hCG in urine to confirm conception.