P8 space physics

Question 1

what is the geocentric model

Answer 1

everything orbited earth with a fixed background of stars

Question 2

what is the heliocentric model

Answer 2

everything rotates around the sun Galileo watched Jupiter rotate and realised it wasn’t rotating round earth

Question 3

explain planetary orbit

Answer 3

gravitational force causes planet to change constantly means the velocity is always changing meaning the force causes the planet to accelerate without increasing speed

Question 4

describe how a protostar is formed turning into a main sequence star

Answer 4

-dust and cloud in the galaxy are drawn together through gravitational force
-temperature and pressure of the cloud push particles together fusing them (hydrogen nuclei fuse to form helium nuclei)
-this creates large amount of energy opposing the collapse of the cloud due to gravity this creates an equilibrium forming a star

Question 5

explain how a neutron star or black hole is formed

Answer 5

-star eventually runs out of gas and equilibrium collapses
-if the star is massive pressure and temperature the core will increase letting heavier elements fuse
-once all fusion happens its to massive to be stable and it folds in on itself creating a supernova which turns into a black hole

Question 6

explain how a white dwarf is created

Answer 6

-when a normal star runs out of gas equilibrium collapses heavier elements fuse but not as much as a massive star
-a lower scale supernova happens and a white dwarf is made

Question 7

explain red shift

Answer 7

-red shift is galaxies moving away from earth
-light from a galaxy has its wavelength “red shifted” getting larger so the frequency decreases making the galaxy appear as if its moving away