N/S Life Flashcards
Sun
One of the hundreds of billions of stars in our galaxy called the Milky Way
Rotation
Earth spinning on it’s own axis
It takes 24 hours
Turns from west to east
(Anticlockwise)
Creates night and day
Orbit- earth
Earths path around the sun
It takes 365 and a quarter days
(Anticlockwise)
Creates the seasons
Summer Solstice
Sun is directly on Tropic of Capricorn
Longest day - shortest night in Southern Hemisphere
21 December
Winter Solstice
Sun is directly on Tropic of Cancer
Shortest day - longest night in Southern Hemisphere
21 June
Equinoxes
Sun is directly on the Equator
Day and night equal length
21 March and 21 September
Leap day
Every 4 years an extra day is added the February to make up for the 4 quarters
Factors that effect seasons
Spherical shape of the earth
Rotation of earth around its own axes
Revolution of the earth in an orbit around the sun
The path around the sun is elliptical (oval)
Axis of earth is at a slight angle to its orbit
Distance of earth from the sun different at different times of year
Autotrophic
Producers
Plants that can produce their own food
Photosynthesis
Carbon Dioxide (CO2) + Water (H2O)
Sunlight
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Chlorophyll
Food (glucose) + Oxygen (O2)
Chloroplast
A cell organelle that is found in green plants
Fuel
An energy source that can be burned to release energy
Fossil Fuels
Energy found in ancient plants
Coal, Crude oil, Natural gas
How fossil fuels were formed
Remains of dead plants/animals covered by layers of mud and soil in swamps
This forms layers and layers of sponge material - peat
It can not rot and perish because no oxygen
Over hundreds of years peat is covered by sand, clay, other minerals - turns into fossils
High pressure compresses peat more until it changes into coal, crude oil or natural gas
Uses of crude oil
Manufacture of Petrol, Paraffin and Diesel
SA does not have many reserves - import
Uses of Coal
Eskom to generate electricity
Sasol to manufacture petrol
Burned to keep warm and cook food
Orbit
A set path around a planet or star
Satellite
Any object that orbits the earth
The moon
Earths only natural satellite
+/- 384 400 km from earth
No atmosphere, water or life
Gravity 6 time less than earth
Diameter a quarter of earth
What is Earths moon called
Luna
Motion of the moon
Turns (rotates) around it’s own axis
Orbits around Earth in 28 days
Moves with Earth around the Sun in 265.25 days
New Moon
When the moon is between the earth and the sun and cannot be seen
Waxing crescent
The moon looks like a sickle. Only a small part of the moon can be seen
First quarter (Half moon)
As the moon moves around Earth, the visible part of the moon becomes larger until it reaches the 1st quarter
