True or False? The Earth completes one full rotation in approximately 24 hours.

True. It takes approximately 24 hours for the Earth to rotate once on its axis.

What causes one Earth year to have 365 days?

One Earth year has 365 days because it takes the Earth 365 days to complete one orbit around the Sun.

What causes day and night on Earth?

Day and night are caused by the rotation of the Earth on its axis.

True or False? The seasons are caused by the tilt of the Earth on its axis only.

False. The seasons are caused by the tilt of the Earth on its axis and its orbit around the Sun once every 365 days.

Define the term equinox .

Equinox occurs when the hours of day and night are the same in both hemispheres.

Define the term summer solstice .

Summer solstice is the longest day of the year when the Sun reaches its highest point above the horizon.

True or False? When it is the summer solstice in the southern hemisphere, it is the winter solstice in the northern hemisphere.

True. When it is the summer solstice in the southern hemisphere, it is the winter solstice in the northern hemisphere.

True or False? The Moon produces its own light.

False. The Moon shines with light reflected from the Sun, it does not produce its own light.

Define the term full Moon .

A full Moon occurs when the Moon is on the opposite side of the Earth from the Sun and appears as a whole circle.

List two reasons why the phases of the Moon occur.

The phases of the Moon occur because: 1. The Moon orbits the Earth once every 28 days. 2. The Moon reflects light from the Sun.

Define the term orbital speed . (Extended Tier Only)

Orbital speed is the average speed of an object as it orbits around a larger object.

True or False? When planets and satellites orbit larger bodies, they move in approximately circular paths. (Extended Tier Only)

True. When a planet orbits the Sun or a satellite orbits a planet, they move in approximately circular paths.

Define the term orbital period . (Extended Tier Only)

Orbital period is the time it takes an object to complete one full orbit around another object.

What is the orbital period of the Earth? (Extended Tier Only)

The orbital period of the Earth is 365 days, the time it takes to complete one orbit around the Sun.

True or False? The orbital radius is measured from the surface of the orbiting body. (Extended Tier Only)

False. The orbital radius is always taken from the centre of mass of the orbiting body.

True or False? An object in a circular orbit has a constant orbital radius. (Extended Tier Only)

True. An object in a circular orbit has a constant orbital radius.

List five objects that make up the Solar System.

Five objects that make up the Solar System are: The Sun Eight planets Satellites (natural and artificial) Dwarf planets Asteroids and comets

State the names of the planets in order of increasing distance from the Sun.

The planets in order of increasing distance from the Sun are: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune

What is an asteroid ?

An asteroid is a small rocky object which orbits the Sun.

Where is the asteroid belt located?

The asteroid belt is located between Mars and Jupiter.

What are comets made of?

Comets are made of dust and ice.

True or False? All objects in the Solar System orbit around the Sun.

False. Planets, dwarf planets, asteroids and comets orbit around the Sun, whereas satellites, such as moons, orbit around planets.

What is the difference between natural and artificial satellites?

A natural satellite is a non-manmade object that orbits a planet, such as a moon. An artificial satellite is a manmade object that can orbit any object in space.

What is an accretion disc ?

An accretion disc is a rotating disc of dust and gas that forms around an object, such as the Sun during its formation.

True or False? The inner planets are small and rocky. The outer planets are large and gaseous.

True. The inner planets (Mercury, Venus, Earth, Mars) are small and rocky. The outer planets (Jupiter, Saturn, Uranus, Neptune) are large and gaseous.

According to the accretion model, what caused the differences in the size and composition of the inner and outer planets?

According to the accretion model: The inner planets are small and rocky because a small proportion of heavy elements were solid closer to the Sun The outer planets are large and gaseous because a large proportion of light elements were solid further from the Sun

True or False? Light travels instantaneously across large distances.

False. Light travels at a constant speed of 3 × 10 8 m/s, therefore, it takes time for light to travel any distance.

True or False? The orbits of planets, minor planets and comets are elliptical. (Extended Tier Only)

True. The orbits of planets, minor planets and comets are elliptical.

Which type of object in the Solar System has the most elongated elliptical orbit? (Extended Tier Only)

Comets have the most elongated elliptical orbits in the Solar System.

True or False? The Sun is at the centre of an elliptical orbit. (Extended Tier Only)

False. When a body moves in a circular orbit, the larger body will be at the centre of the circle. When a body moves in an elliptical orbit, the larger body will be at one of the two foci of the ellipse. Therefore, the Sun is not at the centre of an elliptical orbit.

How does the orbital radius of a planet change with increasing distance from the Sun? (Extended Tier Only)

The orbital radius of a planet increases with increasing distance from the Sun.

How does the orbital period of a planet change with increasing distance from the Sun? (Extended Tier Only)

The orbital period of a planet increases with increasing distance from the Sun.

True or False? The outer planets are denser than the inner planets. (Extended Tier Only)

False. The inner planets are denser than the outer planets.

True or False? Neptune is the coldest planet. (Extended Tier Only)

True. The surface temperature of a planet tends to decrease with distance from the Sun (with the exception of Venus). Neptune is the furthest planet from the Sun, therefore, it is the coldest planet.

True or False? The surface gravity on Saturn is greater than on Earth. (Extended Tier Only)

True. Surface gravity depends on the mass of a planet. Values of surface gravity are greater on the giant outer planets than on the small inner planets. Therefore, the surface gravity on Saturn is greater than on Earth.

Weight is the force acting on an object due to gravitational attraction.

State the meaning of gravitational field strength .

Gravitational field strength is the strength of the gravitational pull exerted by an object, such as a planet or moon, on another object on or near its surface.

True or False? Gravitational field strength is constant at the surface of a given planet.

True. Gravitational field strength is constant at the surface of a given planet, but it decreases with distance above the planet's surface.

On which planet in the Solar System would you weigh the heaviest ?

The greater the gravitational field strength of a planet, the greater the measured weight of a person standing on its surface. Therefore, you would weigh the heaviest on Jupiter , as this is the largest (most massive) planet.

In which direction does the gravitational force of an orbiting body act?

The gravitational force exerted on an orbiting body acts towards the centre of the larger body it is orbiting.

True or False? The strength of the Sun's gravitational field increases as the distance from the Sun increases. (Extended Tier Only)

False. The strength of the Sun's gravitational field decreases as the distance from the Sun increases.

What happens to the orbital speed of a planet as the distance from the Sun increases? (Extended Tier Only)

The orbital speed of a planet decreases as the distance from the Sun increases.

How does the speed of a comet change as it approaches the Sun? (Extended Tier Only)

The speed of a comet changes as it approaches the Sun because it speeds up .

In terms of conservation of energy, why does the speed of a comet change as it approaches the Sun? (Extended Tier Only)

In terms of conservation of energy, when a comet approaches the Sun, it gains kinetic energy and loses gravitational potential energy. This causes it to speed up .

IGCSEPhysicsCambridge (CIE)Flashcards

6.1 Earth & The Solar System (Cambridge (CIE) IGCSE Physics)

Flashcards

1/50

Front6.1.1 The Earth, Moon & Sun
True or False?
The Earth completes one full rotation in approximately 24 hours.

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Cards in this collection (50)

True or False?
The Earth completes one full rotation in approximately 24 hours.
True.
It takes approximately 24 hours for the Earth to rotate once on its axis.
What causes one Earth year to have 365 days?
One Earth year has 365 days because it takes the Earth 365 days to complete one orbit around the Sun.
What causes day and night on Earth?
Day and night are caused by the rotation of the Earth on its axis.
True or False?
The seasons are caused by the tilt of the Earth on its axis only.
False.
The seasons are caused by the tilt of the Earth on its axis and its orbit around the Sun once every 365 days.
Define the term equinox.
Equinox occurs when the hours of day and night are the same in both hemispheres.
Define the term summer solstice.
Summer solstice is the longest day of the year when the Sun reaches its highest point above the horizon.
True or False?
When it is the summer solstice in the southern hemisphere, it is the winter solstice in the northern hemisphere.
True.
When it is the summer solstice in the southern hemisphere, it is the winter solstice in the northern hemisphere.
True or False?
The Moon produces its own light.
False.
The Moon shines with light reflected from the Sun, it does not produce its own light.
Define the term full Moon.
A full Moon occurs when the Moon is on the opposite side of the Earth from the Sun and appears as a whole circle.
List two reasons why the phases of the Moon occur.
The phases of the Moon occur because:
1. The Moon orbits the Earth once every 28 days.
2. The Moon reflects light from the Sun.
Define the term orbital speed. (Extended Tier Only)
Orbital speed is the average speed of an object as it orbits around a larger object.
True or False?
When planets and satellites orbit larger bodies, they move in approximately circular paths. (Extended Tier Only)
True.
When a planet orbits the Sun or a satellite orbits a planet, they move in approximately circular paths.
State the equation for calculating orbital speed in terms of distance and time. (Extended Tier Only)
The equation for calculating orbital speed is $s p e e d = \frac{d i s t a n c e}{t i m e}$
Define the term orbital period. (Extended Tier Only)
Orbital period is the time it takes an object to complete one full orbit around another object.
What is the orbital period of the Earth? (Extended Tier Only)
The orbital period of the Earth is 365 days, the time it takes to complete one orbit around the Sun.
True or False?
The orbital radius is measured from the surface of the orbiting body. (Extended Tier Only)
False.
The orbital radius is always taken from the centre of mass of the orbiting body.
What is the distance travelled by an object moving in circular motion in one orbit? (Extended Tier Only)
The distance travelled by an object moving in circular motion is equal to the circumference of the orbit = $2 π r$ , where r is the radius of the orbit.
True or False?
An object in a circular orbit has a constant orbital radius. (Extended Tier Only)
True.
An object in a circular orbit has a constant orbital radius.
State the equation for orbital speed v, in terms of orbital radius r and time t. (Extended Tier Only)
The equation for orbital speed is $v = \frac{2 π r}{T}$
Where:
- $v$ = orbital speed, measured in m/s
- $r$ = orbital radius, measured in m
- $T$ = orbital period, measured in s
True or False?
The orbital radius of a satellite in orbit around the Earth is equal to:
radius of the Earth + height above the Earth's surface
(Extended Tier Only)
True.
The orbital radius of a satellite orbiting the Earth is $r = R + h$
Where:
- $r$ = orbital radius of the satellite, measured in m
- $R$ = radius of the Earth, measured in m
- $h$ = height above the Earth's surface, measured in m
List five objects that make up the Solar System.
Five objects that make up the Solar System are:
1. The Sun
2. Eight planets
3. Satellites (natural and artificial)
4. Dwarf planets
5. Asteroids and comets
State the names of the planets in order of increasing distance from the Sun.
The planets in order of increasing distance from the Sun are:
Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune
What is an asteroid?
An asteroid is a small rocky object which orbits the Sun.
Where is the asteroid belt located?
The asteroid belt is located between Mars and Jupiter.
What are comets made of?
Comets are made of dust and ice.
True or False?
All objects in the Solar System orbit around the Sun.
False.
Planets, dwarf planets, asteroids and comets orbit around the Sun, whereas satellites, such as moons, orbit around planets.
What is the difference between natural and artificial satellites?
A natural satellite is a non-manmade object that orbits a planet, such as a moon.
An artificial satellite is a manmade object that can orbit any object in space.
What is an accretion disc?
An accretion disc is a rotating disc of dust and gas that forms around an object, such as the Sun during its formation.
True or False?
The inner planets are small and rocky.
The outer planets are large and gaseous.
True.
The inner planets (Mercury, Venus, Earth, Mars) are small and rocky.
The outer planets (Jupiter, Saturn, Uranus, Neptune) are large and gaseous.
According to the accretion model, what caused the differences in the size and composition of the inner and outer planets?
According to the accretion model:
- The inner planets are small and rocky because a small proportion of heavy elements were solid closer to the Sun
- The outer planets are large and gaseous because a large proportion of light elements were solid further from the Sun
True or False?
Light travels instantaneously across large distances.
False.
Light travels at a constant speed of 3 × 10⁸ m/s, therefore, it takes time for light to travel any distance.
What equation can be used to calculate the time taken for light to travel a certain distance?
The equation that can be used to calculate the time taken for light to travel a certain distance is:
$t i m e = \frac{d i s t a n c e}{s p e e d}$
True or False?
The orbits of planets, minor planets and comets are elliptical. (Extended Tier Only)
True.
The orbits of planets, minor planets and comets are elliptical.
Which type of object in the Solar System has the most elongated elliptical orbit? (Extended Tier Only)
Comets have the most elongated elliptical orbits in the Solar System.
True or False?
The Sun is at the centre of an elliptical orbit. (Extended Tier Only)
False.
When a body moves in a circular orbit, the larger body will be at the centre of the circle.
When a body moves in an elliptical orbit, the larger body will be at one of the two foci of the ellipse.
Therefore, the Sun is not at the centre of an elliptical orbit.
How does the orbital radius of a planet change with increasing distance from the Sun? (Extended Tier Only)
The orbital radius of a planet increases with increasing distance from the Sun.
How does the orbital period of a planet change with increasing distance from the Sun? (Extended Tier Only)
The orbital period of a planet increases with increasing distance from the Sun.
True or False?
The outer planets are denser than the inner planets. (Extended Tier Only)
False.
The inner planets are denser than the outer planets.
True or False?
Neptune is the coldest planet. (Extended Tier Only)
True.
The surface temperature of a planet tends to decrease with distance from the Sun (with the exception of Venus).
Neptune is the furthest planet from the Sun, therefore, it is the coldest planet.
True or False?
The surface gravity on Saturn is greater than on Earth. (Extended Tier Only)
True.
Surface gravity depends on the mass of a planet.
Values of surface gravity are greater on the giant outer planets than on the small inner planets.
Therefore, the surface gravity on Saturn is greater than on Earth.
Define weight.
Weight is the force acting on an object due to gravitational attraction.
What is the equation for weight?
The equation for weight is: $W = m g$
Where:
- $W$ = weight, measured in newtons (N)
- $m$ = mass of the object, measured in kilograms (kg)
- $g$ = gravitational field strength, measured in newtons per kilogram (N/kg)
State the meaning of gravitational field strength.
Gravitational field strength is the strength of the gravitational pull exerted by an object, such as a planet or moon, on another object on or near its surface.
True or False?
Gravitational field strength is constant at the surface of a given planet.
True.
Gravitational field strength is constant at the surface of a given planet, but it decreases with distance above the planet's surface.
On which planet in the Solar System would you weigh the heaviest?
The greater the gravitational field strength of a planet, the greater the measured weight of a person standing on its surface.
Therefore, you would weigh the heaviest on Jupiter, as this is the largest (most massive) planet.
In which direction does the gravitational force of an orbiting body act?
The gravitational force exerted on an orbiting body acts towards the centre of the larger body it is orbiting.
True or False?
The strength of the Sun's gravitational field increases as the distance from the Sun increases. (Extended Tier Only)
False.
The strength of the Sun's gravitational field decreases as the distance from the Sun increases.
What happens to the orbital speed of a planet as the distance from the Sun increases? (Extended Tier Only)
The orbital speed of a planet decreases as the distance from the Sun increases.
How does the speed of a comet change as it approaches the Sun? (Extended Tier Only)
The speed of a comet changes as it approaches the Sun because it speeds up.
In terms of conservation of energy, why does the speed of a comet change as it approaches the Sun? (Extended Tier Only)
In terms of conservation of energy, when a comet approaches the Sun, it gains kinetic energy and loses gravitational potential energy. This causes it to speed up.