The basics of physics - Kepler Learning

Explore the universe's 13.8 billion years history, from the big bang and space expansion to dark matter and dark energy, and how atoms formed as the cosmos keeps expanding.

Trace the shift from geocentric to heliocentric, with Copernicus, Galileo, and Kepler showing elliptical orbits and gravity-driven speeds, leading to the sun's place among stars in the Milky Way.

Learn how stars form from nebulae under gravity and glow in colors from red to blue. See how constellations and galaxies organize billions of stars in the Milky Way.

Explore how forces affect direction, speed, and shape, read forces as vectors in newton units, and compare friction types, mass, weight, and gravity.

Explore Newton's laws, inertia, gravity, and torque, and see how mass and acceleration drive motion through lever arms.

Compare speed and velocity, noting velocity as a direction-aware vector described by arrows. Apply unit conversions, the svt formula, and concepts of acceleration, gravity, freefall, air resistance, and circular motion.

Explain how pressure determines whether boots sink in snow or a bird stays above the surface, using the formula pressure equals force over area and the units newton and pascal.

Calculate ground pressure by dividing weight by contact area; with a 100 kg mass on an 8 m^2 ground area, weight is 1000 N and pressure is 125 Pa.

Learn how air pressure, density, and lift govern flight and everyday effects, from pressure-area examples with knives to hot air balloons, and apply Bernoulli's principle to aircraft wings.

Discover how Bernoulli's principle and Newton's third law generate lift on aircraft by pressure differences between wing surfaces, illustrated by rocket launch dynamics and downward air deflection.

Explore magnetism by examining magnets with north and south poles, attraction and repulsion, and how heat affects magnets at the Curie point, with iron, nickel, and cobalt as examples.

Permanent magnets have a constant magnetic field with a north and south side; temporary magnets form poles only in contact with a field and lose magnetism when contact ends.

Learn how current and voltage relate in a battery circuit: electrons flow from negative to positive, creating a potential difference measured in volts that drives current and lights the lamp.

Compare series and parallel lamp circuits to see voltage sharing, brightness differences, and why series breaks if a lamp is removed, while parallel keeps others lit.

Explore how resistance blocks current and distinguishes insulators, which prevent flow due to high resistance, from conductors like copper, silver, and gold that conduct electricity.

Explore ohm's law and how current, voltage, and resistance relate through V = I × R, showing how resistance lowers current. 9 V and 0.9 A yield 10 ohms.

Explore electrical power as the rate of electron flow, measured in watts and kilowatts, and learn to convert watts to kilowatts to calculate energy in kilowatt-hours.

Explore how moving electrons create magnetic fields and how moving magnets induce electron flow, converting kinetic energy to electricity in generators and coils that power lamps.

Explore direct current, where electrons move in one direction from a battery, and alternating current, where electrons reverse direction in wall sockets at 50 Hz.

Transformers increase or decrease voltage in electrical energy, using two coils on an iron core and alternating current to transfer voltage from 230V to 5V for devices.

The sun's rays heat Earth's surfaces unevenly, driving weather and climate patterns. Water exists in solid, liquid, and gaseous forms with melting, evaporation, condensation, freezing, sublimation, and deposition.

Explore how warm air holds more moisture than cold air. See how rising air cools and increases relative humidity until the dew point forms clouds.

Heat from the ground drives warm air upward until it cools to the dew point, forming convective clouds such as cumulus; orographic and front clouds arise when air saturates.

Explore how surface heating drives convection to form cumulonimbus clouds with showers and thunder, and how dew point and terrain lifting yield low, medium, and high cloud classifications by altitude.

Identify stratus, altostratus, altocumulus, cirrus, and nimbostratus clouds, their typical altitudes, and their precipitation patterns, including drizzle, prolonged rain, or snow.

Observe how fronts form when warm and cold air meet, with clouds forming. Rising warm air above cold air drives warm fronts, increasing humidity and precipitation.

Measure air pressure in hectopascals; it varies with air and forms low pressure cyclones anticlockwise in northern hemisphere, with rising air cooling to form clouds and high pressure anticyclones clockwise.

Wind arises from pressure differences, blowing from high to low pressure; isobars map the pressure, while a sea breeze forms by daytime land heating and night coastal circulation.

Understand how the troposphere hosts weather up to the tropopause, how high and low pressure shape clouds and climate, and how Hadley, Ferrel, and polar cells create highs and lows.

Explain how the greenhouse effect warms Earth, driven by greenhouse gases like water vapor and carbon dioxide that trap heat and affect the radiation balance.

Analyze how human activities raise carbon dioxide and emissions from fossil fuels, transport, agriculture, and forestry, driving acid rain and smog; and how phosphorus from farming causes algal blooms.

Sun rays include UVA, UVB, and UVC; the ozone blocks UVB and UVC, while UVA passes through. Excess exposure risks skin cancer, and freon-driven ozone depletion peaked over Antarctica August–October.

Global warming drives stronger winds and more storms, melting Arctic ice and threatening wildlife and harvests. The Paris Agreement aims to limit warming to 1.5°C and shift to renewable energy.

Sun rays heat the ground and warm the bottom atmosphere through conduction; cloud-free days are warmer, and cloudy conditions reflect radiant energy and keep heat, while cloud-free nights cool faster.

Sound arises from vibrating objects that cause densifications and rarefactions in air, such as voices. It travels through air at 340 m/s, spreads in all directions, and weakens with distance.

Explore how sound waves are sine waves with wavelength and amplitude, where shorter wavelengths yield higher sounds and longer wavelengths yield lower sounds, with frequency in hertz, ultrasound, and infrasound.

Explore resonance as objects oscillating with sound to amplify it. Acoustic guitars use a vibrating built-in box as an amplifier, while electric guitars require external speakers to boost sound.

Explore how sound waves bounce to create echoes via reflection, and how room acoustics, absorption, and reverberation shape listening in furnished and unfurnished rooms.

Explore the Doppler effect as sound waves compress when a moving car approaches. They stretch as it recedes, causing higher pitch when approaching and lower pitch when moving away.

Explore how hearing and balance arise from sound pressure waves that vibrate the eardrum and middle ear bones, translating through inner ear and cochlea to the auditory nerve and brain.

Explore how noise affects hearing and can lead to hearing loss, distinguish sensorineural from conductive impairment, and learn how ear blockage, age, infection, or earwax impact outcomes.

Explore how light shifted from a particle concept to a wave, then understand electromagnetic waves with electric and magnetic fields, visible to the eye, and light’s speeds in different media.

Explain how wavelengths define colors from red to violet, define ultraviolet, infrared, and white light, and discuss health risks, ozone protection, and practical uses like tooth whitening and night vision.

Explore how energy transforms across forms, from electrical to radiant light in lamps, from nuclear to radiant energy in the sun, and from radiant to electrical in solar cells.

Explore how light reflects off surfaces and follows the law of reflection, with equal angles to the normal, and refracts between media, enabling total internal reflection in fiber optics.

Oscillating in all directions, light waves from the sun consist of electric and magnetic fields, and reflection polarizes light, letting polarized sunglasses reduce glare.

Explore how lenses refract light, comparing convex (positive, collecting) and concave (negative, diffusing) lenses, their focal points and focal lengths, with examples like cameras, eyeglasses, and magnifying glasses.

Explore light refraction in the eye, forming an image at the cornea, and how myopia, hypermetropia, and astigmatism affect vision, with concave and convex lenses correcting focus on the cornea.

Reflect or absorb photons, converting energy into heat when they strike skin. Describe wavelength-dependent energy, color dispersion in prisms, and how refraction changes light direction.

Explore how work, energy, and power relate and how energy transforms from motion to electrical energy. Trace how humans harness wind, water, and sources, guided by the conservation of energy.

Explore kinetic, potential, and mechanical energy, and learn how mass, velocity, height, and gravity transform energy from one form to another, with real-world examples.

Explore energy quality as the ability to convert energy forms with minimal heat loss. No perpetual motion exists due to heat loss, keeping the quality factor near 1.0.

Define power as energy converted per unit time, measured in watts (joules per second). High power means fast task execution; low power means slow execution.

Explore how work is defined as force times distance in physics, with gravity, friction, and examples like lifting a bag and pushing a box, measured in newtons and joules.

Explore how energy storage works across batteries, dams, and various energy types—solar, magnetic, electrical, chemical, and nuclear energy from fission.

Explore how solar, wind, hydro, coal, and nuclear power plants convert energy into electrical power, and how inverters transform direct current to alternating current for home use.

Explore the advantages and limitations of solar, wind, hydro, coal, and nuclear power, highlighting renewability, emissions, weather dependence, and environmental impacts.