Space

Question 1

At what angle is the Earth’s axis tilted at?

Answer 1

23.5 degrees

Question 2

What is the formula for the average orbital speed?

Answer 2

v = 2 pi r / T
Average orbital speed (m/s) = 2(pi)(average radius between centre of rotation (m)) divided by time for one complete orbit (s)

Question 3

Define solar winds

Answer 3

High speed particles leaving the sun

Question 4

What affects the gravitational field strength of a planet at its surface?

Answer 4

Mass of the planet
Gets weaker as the distance from the planet increases.

Question 5

Describe the life-cycle of a star.

Answer 5

Stars are born from interstellar clouds of gas and dust
Gravity pulls the cloud of hydrogen and dust together to form a stellar nebula
Stellar nebula gradually collapses under its own gravity.
As it collapses, temperature increases and starts to emit light; forms a protostar.

ROUTE 1:

If star formed has relatively low mass, it forms an average sized stable star. Force of gravity is balanced by outward force due to high temperatures in centre.
Average stars start to run out of hydrogen; outer layers expand, forming a red giant.
Red giants eventually run out of fuel, and the outer layers will spread out further while cooling down, eventually becoming a loose cloud of gas and dust.
After outer layers of the red giant spread out, the core of the star remains. No fusion happens, but temperature is still very high, forming a white dwarf.

ROUTE 2:

If the star formed has a relatively high mass, forms a massive stable star. Force of gravity balanced by outward force due to high temperatures in centre.
When massive stars run out of hydrogen, outer layers expand and a red supergiant is formed.
When the red supergiant becomes so massive, it has a huge amount of gravity. When star runs out of fuel, gravity pulls all the matter back to the centre and the star explodes, forming a supernova.
After the supernova, the core of the star remains, however it still has so much mass and gravity that atoms cannot exist and neutrons form instead, forming a neutron star.
If the star’s core is big enough, even neutrons cannot exist because gravity is crushing them together with so much force.
All matter in the core of the star is crushed together to a single point, creating the most dense object in the Universe, a black hole.