Physics test 8th grade #2 Flashcards
Why are summers generally warmer than winters?
The angle that the sunlight hits the earth is steeper in the winter and more perpendicular in the summer
The days are longer, meaning that the sun is out for longer
Where on Earth are seasons NOT very different?
Near the equator, seasons are not very different because the equator is hit by the sun each day at the same angle. The poles remain cool because they are never in the direct path of sunlight
What are the two major ways the Earth moves?
Rotation
Revolution
What is rotation?
The spinning of the Earth on its axis
Rotation causes day and night because as Earth turns from west to east, the sun appears to move from east to west. The part of the Earth that doesn’t face the sun is night
What is the imaginary line around which the Earth spins?
Axis
Which way does the Earth rotate?
The Earth rotates eastward or west to east
How does the Sun appear to move in the sky?
The sun appears to move east to west, rising in the east and setting in the west
What is the name of one full rotation?
One rotation is called a day
How long does one full rotation take in hours, minutes, and seconds?
24 hours
1440 minutes
86400 seconds
What is a revolution?
The movement of one object around another
How long does it take for the Earth to move around the Sun?
365 days
What is the name of one full revolution?
A year
What shape is the Earth’s path around the Sun?
Earth’s orbit path is a slightly elongated circle or ellipse.
How long does a full revolution take in days, hours, minutes, seconds?
365.25 days
8766 hours
525960 minutes
31557600 seconds
What season is it in the Northern Hemisphere when the Earth is closest to the Sun?
It is winter in january when the Earth is closest to the sun
How can you tell what season it is based on the position of the Earth?
When the northern hemisphere is directed away from the sun it is winter in the northern hemisphere. If the northern hemisphere is pointed towards the sun, it is summer in the northern hemisphere.
What is a calendar?
A system of organizing time that defines the beginning, length, and divisions of a year
The motions of which two bodies are used to make a calendar?
The motions of the Earth and the Moon are used to make a calendar
What does a calendar organize? Explain
A calendar organizes time that defines the beginning, length, and divisions of a year.
What are the three main divisions of time used in a calendar?
The three main divisions of time used in a calendar are years, months, and days
How is each of the above three connected to the movements previously identified?
A year is a full revolution of the sun, a month corresponds to the cycle of the moon, which takes around 30 days to complete, and days refer to one full rotation on its axis.
Where do you need to be to have four distinct seasons?
You need to be in the middle between the poles and the equator - above the tropics of capricorn and cancer and below the poles
How does the temperature change generally as you go towards the poles?
It is warmer near the equator and gets colder as you move towards the poles
How does the sunlight hit the Earth’s surface near the equator?
Near the equator, sunlight hits the Earth’s surface from overhead
How does the sunlight hit the Earth’s surface near the poles
Near the poles, sunlight hits the earth’s surface at a steep angle
Why is it cooler near the poles?
It is cooler near the poles because the sun hits at a steep angle and is not able to cover a large area. The less sun, the colder it is
Where is the sunlight most direct?
Near the equator, sunlight does not spread very far. The sun’s energy is concentrated in a smaller area
How does sunlight hit the poles?
Near the poles, the same amount of sunlight spreads over a greater area, therefore lowering the temperature
Why does the Earth have seasons?
Earth has seasons because its axis is tilted as it revolves around the sun
What would happen if Earth’s axis was straight up and down?
Temperatures in an area would remain fairly constant year round
In what situation would Earth have no seasons?
Earth would have no seasons if its axis had no tilt
What is the given angle of tilt of the Earth from the vertical?
The tilt of Earth is 23.5°
Is the angle of tilt always towards the Sun?
No, the angle of tilt is not always towards the sun. As Earth orbits the sun, its tilt is always facing the same direction. So if in September it is facing towards the sun, then in March, the tilt is away from the sun. The Earth is always tilted towards the north star (north)
In December…
The Southern end of the axis is tilted __ the Sun.
The Sun is __ in the sky.
The Sun’s rays are less slanted and so are concentrated over a
___ area.
There are ___ hours of daylight.
It is ____ in the Southern Hemisphere
The Southern end of the axis is tilted towards the Sun.
The Sun is higher in the sky.
The Sun’s rays are less slanted and so are concentrated over a
smaller area.
There are more hours of daylight.
It is summer in the Southern Hemisphere
In June…
The Southern end of the axis is tilted ___ from the Sun.
The Sun is ___ in the sky.
The Sun’s rays are ___ slanted and so spread over a bigger area.
There are ___ hours of daylight.
It is ____ in the Southern Hemisphere
The Southern end of the axis is tilted away from the Sun.
The Sun is lower in the sky.
The Sun’s rays are more slanted and so spread over a bigger area.
There are less hours of daylight.
It is winter in the Southern Hemisphere
What are the planets with tilts less than the Earth
Mercury, Jupiter, venus
What is the planet on its side?
Uranus
What is the day when the sun appears furthest North of the equator called?
When the sun appears furthest north of the equator it is the summer solstice in the northern hemisphere and the winter solstice in the southern hemisphere.
When is the summer solstice?
June 21st
When is the winter solstice?
December 21st
How does June 21st affect day length?
Northern Hemisphere: this is the longest day of the year
Southern Hemisphere: This is the shortest day of the year
How does December 21st affect day length?
Northern Hemisphere: this is the shortest day of the year
Southern Hemisphere: This is the longest day of the year
How does the Sun appear in the sky in the Northern Hemisphere on June 21st?
The sun is high at midday and is the most north during the day than any other time of the year.
How does the Sun appear in the sky in the Southern Hemisphere on this day?
In the southern hemisphere, the sun is low at midday and is mainly south during the day.
When are the equinoxes?
Halfway between the solstices when neither hemisphere is tilted toward the sun
Where is the Sun directly overhead on the day of the Equinox?
The sun is directly overhead on the day of the Equinox at the equator
What does the word Equinox mean?
Equinox means equal night
How long are the days on the Equinoxes? Where does this day length apply?
The days and nights are around 12 hours long everywhere, hence its name
Give the names and the dates of the two equinoxes
The vernal equinox is on March 21st (spring) and the autumnal equinox occurs around September 22 (fall)
Where does the sun rise on the June solstice in the northern and southern hemisphere?
It rises north east
Where does the sun rise on the december solstice in the northern and southern hemisphere?
It rises South East
Where does the sun rise on both equinoxes in the northern and southern hemisphere?
It rises exactly east
Season definition
A period of the year that is distinguished by special climate conditions
Definition of tilt of the earth
Resulted from the angle of the collision that formed the moon
Mercury facts
Thomas Harriot and Galileo Galilei discovered it
Mercury is the smallest and closest planet to the sun
Sections of the planet have ice while others are extremely hot
No moons, no rings, no atmosphere
Eliptical orbit and slow rotation
Rotation period = 59 earth days
No seasons
Revolution period = 88 days
Uranus facts
Discovered by William Herschel
Johann Bode made it recognized as a planet
Atmosphere made of hydrogen, helium, methane (this gives it the blue color, ammonia, and water
27 moons named after Shakespeare characters
Two sets of rings, inner & outer
Extreme tilt caused by a collision long time ago
98° tilt (practically on its side)
Poles are exposed to the sun for a long period of time and vise versa. (one is constant daytime and the other in nighttime) 21 years to be exact
day-night cycle/rotation period is 17 hours
42 years to make a complete revolution
