Hard Content :( Flashcards
Define planet:
A natural object that orbits the sun. Must be spherical and be in its own orbit.
Define moon:
natural object that orbits a planet
Define Oort Cloud:
Region of icy particles on outside of our solar system
Define comet:
made of ice and dust, came from the edge of our solar system
Define universe:
a collection of galaxies
If a main sequence star has a larger mass than the sun what will happen to it?
super red giant, supernova +black hole -neutron star
If a main sequence star has a mass similar to the sun, what will happen to it?
red giant, white dwarf, red/black dwarf
How does a main sequence star turn into a red/super red giant?
Runs out of hydrogen fuel so begins to fuse helium, causing star to collapse and start dying
How is a white dwarf formed?
No more fusion occurs in red/super red giant because helium is used up. star begins to collapse and die.
How is a black/red dwarf formed?
when white dwarf no longer has energy it cools and eventually turns black
How is a supernova formed?
when a super red giant runs out of fuel it begins to collapse but because the star is so big it will implode and radiate matter into the galaxy
How is a neutron star formed?
If there is little mass left after supernova, all protons and electrons collapse to form neutrons
How is a black hole formed?
If there is high mass, star continues to collapse until it reaches zero volume
What colour is a celestial object if it is moving towards you?
blue
What rule is used for electromagnetic induction?
right hand rule - thumb is force, index is magnetic field direction and middle is conventional current
What is CMBR?
radiation from the Big Bang that has been stretched and is now present in our surroundings
What is the equation for red shift calculations?
observed wavelength/original wavelength = recessional velocity/speed of light
Define the Doppler effect:
When the apparent wavelength and frequency changes due to the movement of the source towards or away from an observer
How is red shift of galaxies proof of the Big Bang?
- red shift of galaxies shows that all galaxies are moving away from each other
- this implies they are expanding
- the further away, the faster the galaxies are moving
- all galaxies have been moving away from us for the same amount of time so they must have started in the same place
What is voltage?
the energy transferred per unit charge
What is the equation linking current, charge and time?
current = charge/time
Define charging by friction:
apply frictional force between two insulators creating ‘permanent charge’
What is Ohm’s law?
ohm’s law states that the voltage and current are proportional for a component where there is a fixed resistance
How does temperature affect resistance?
higher resistance as ions vibrate more as they have more kinetic energy, increasing the collisions
What is a conductor?
delocalised electrons
What is an insulator?
localised electrons
Define power in an electricity context:
rate of energy tranfer
What colour is the live wire?
brown
What colour is the neutral wire?
blue
What is the first gas law?
the temperature is proportional to the pressure when there is a constant volume and number of particles
What is the equation linking pressure and temperature?
P1/T1=P2/T2