cosmos and motion flashcards

Quantitative: Numerical.

Qualitative: Descriptive.

Speed: Rate.

Velocity: Direction.

Motion: Force.

Force: Push or pull, causes a change in motion.

Uniform motion: Constant velocity.

Scalar: Quantity.

Vector: Quantity and direction.

Distance: Total length.

Displacement: Direct, origin.

Acceleration: Rate of change, speed and/or direction.

Deceleration: Negative.

First law: Remain at rest, continue in motion, same velocity, unbalanced external force.

Second law: Unbalanced external force, motion changes, F=ma.

Third law: Equal and opposite reaction, consequences relative to mass.

Gravity: Force, any 2 masses.

Gravitational attraction: Affected by mass and distance.

Mass: Amount of matter, kilos.

Weight: Gravitational force, Earth attracts towards centre, Newtons.

Acceleration due to gravity: 9.8 ms-1 regardless of mass, less, drag force.

Drag force: Resistance force, object moving through fluid, influenced by sa, size and speed.

Terminal velocity: Maximum speed, drag force = weight, cannot accelerate.

Wave: Disturbance, transfers energy.

Mechanical wave: Wave, medium.

Longitudinal wave: Parallel, like a spring.

Transverse wave: Perpendicular, shaken rope.

Wavelength: Distance, crest to crest (m).

Amplitude: Maximum displacement from mean position (m).

Oscillation: Repeated movement.

Period: Time, one oscillation (s).

Frequency: Amount of waves, certain point, 1 second (Hz).

Electromagnetic spectrum: Spectrum of light, transfers energy through electric and magnetic fields.

Wave properties: Speed, period, frequency, amplitude, wavelength.

Electromagnetic radiation: Emission of energy, travels at speed of light in vacuum.

Vacuum: No matter.

Electromagnetic waves: self propogating, doesn’t need a medium.

Radio waves: Space and communication.

Microwave waves: Cell phones, consumer use.

Infrared waves: Detected in heat, used in cooking and heat lamps.

Visible light waves: Human eye detect, sight and photography.

Ionised radiation: Electromagnetic waves have enough energy to ionise radiation, can be harmful.

Ultraviolet waves: Can cause skin cancer and blindness, used for phototherapy and suntanning.

X-ray waves: Can cause cancer, used in medicine and imaging.

Gamma waves: Higher penetrative through matter, emitted by radiative elements, used for cancer treatment.

Absorption: Transfer of energy of wave to matter it travels through.

Reflection: Bouncing back of light, hitting a surface.

Refraction: Change in direction of wave, change in medium.

Concave mirror: Converging parallel light rays, single point.

Convex mirror: Diverging parallel light rays, spread.

Star: Luminous, ball of gas, hydrogen + helium, gravity.

Galaxy: Collection, gas + dust + stars + solar systems, gravity.

Planet: Celestial body, orbits a star, spherical shape due to gravity, no similarly heavy objects in orbit.

Nebula: Giant cloud, dust + gas, star-forming region.

Solar system: Star + group of orbiting heavenly bodies.

Black hole: Strong gravity, light.

Red giant: Dying star, hydrogen for nuclear fusion.

White dwarf: Hot core of a star, after it runs out of fuel.

Supernova: Explosion, heat + light + pressure, creates elements heavier than group 1, distributed.

Neutron star: Neutrons packed together, pressure, fuses electrons and protons, result of supernova.

HR diagram: Relationship between surface temperature and luminosity (also can include magnitude, spectral class and colour).

Spectral class: surface temp + atmosphere pressure.

Luminosity: Energy emitted per second, surface of star, influenced by surface temp + size + distance.

Hubble’s law: Distance between galaxies are ever-expanding, red shift, Doppler’s effect.

Red shift: DIstance behind moving galaxy, expanding waves, measured.

Doppler’s effect: Increase/decrease of waves, moving object.

Hubble’s deep view image: Image of old galaxies, more distance = older image.

Cosmic background radiation (CMBR): Microwave radiation, remnants of light from Big Bang, evenly spread, -270 degrees Celsius.

Abundance of hydrogen and helium: Theoritically, universe is very light, easiest to form.

Steady state theory: Universe is ever-expanding, creating new matter, average density.

Brightness: Luminosity + distance from us.

Big bang theory: Single point, expanded.

13.8 million years ago: Space + time + energy + matter, rapidly expands and cools.

Immediately after: Quarks and leptons + electrons and protons form, no more nuclear fusion.

20 min - 380,000 after: Energy in electromagnetic waves, exists as ionised gas.

380,000 after: Transparent, energy + temp decreases.

200 million - 1 billion years after: Stars and galaxies form and gather.

9.2 billion after: Sun formed.

13.2 billion after: Pangea and after starts.