Which statement about geostationary satellites is correct?
They appear to be in a fixed position relative to a point on the Earth.
They are in a polar orbit.
They are positioned 400 km above the Earth’s surface.
They take 2 hours to orbit the Earth.
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The average temperature on the Earth has increased over the last century.
Which statement explains why?
Radiation absorbed by the Earth has decreased.
Radiation absorbed is less than radiation emitted.
Radiation absorbed is greater than radiation emitted.
Radiation emitted by the Earth has increased.
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Which statement about a star that explodes into a supernova is correct?
The star has more mass than the sun.
The star is older than the sun.
The star will become a white dwarf.
The star’s core expands.
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A planet moves in a circular orbit around its star.
Which statement is correct?
The planet travels at changing speed and changing velocity.
The planet travels at changing speed but constant velocity.
The planet travels at constant speed and velocity.
The planet travels at constant speed but changing velocity.
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An artificial satellite is kept in its low polar orbit by a gravity force from a planet.
The satellite is moved to a higher orbit above the planet.
Which statement is correct about the satellite in this higher orbit?
The force of gravity is greater and its speed decreases.
The force of gravity is greater and its speed increases.
The force of gravity is less and its speed decreases.
The force of gravity is less and its speed increases.
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Planet Ocra is in a circular orbit around a star.
Which statement is correct?
The acceleration of Ocra is zero.
The speed of Ocra is changing.
The velocity of Ocra is changing.
The velocity of Ocra is zero.
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An artificial satellite orbits the Earth in a circular path.
The satellite is moved further away from Earth to another orbit.
Which row in the table is correct?
| Force of gravity | Speed in orbit | Time period | |
| A | decreases | decreases | decreases |
| B | decreases | decreases | increases |
| C | decreases | increases | increases |
| D | increases | increases | increases |
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Which statement is correct about geostationary satellites?
They are above the equator and they orbit the Earth in about 90 minutes at a high orbit.
They are above the equator and they orbit the Earth in 24 hours at a high orbit.
They are above the equator and they orbit the Earth in 24 hours at a low orbit.
They are above the poles and they orbit the Earth in 24 hours at a low orbit.
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How was the Sun formed?
From dust and gas pulled together by gravity leading to a fission reaction.
From dust and gas pulled together by gravity leading to a fusion reaction.
From dust and gas pushed together by gravity leading to a fission reaction.
From dust and gas pushed together by gravity leading to a fusion reaction.
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The Sun was formed from a cloud of dust and gas.
Which force brought together the particles of the cloud?
Electrostatic
Frictional
Gravitational
Magnetic
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Which statement is evidence for an expanding universe?
Light from galaxies is red shifted.
Nuclear fusion occurs in stars.
Many stars have orbiting planets.
Stars were formed from dust and gas.
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Which row A, B, C or D, describes what has happened to light that has undergone red shift?
| Wavelength | Frequency | |
| A | Decreases | Decreases |
| B | Decreases | Increases |
| C | Increases | Decreases |
| D | Increases | Increases |
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The table contains statements about red-shift and galaxies.
Which row in the table is correct?
| Statement 1 | Statement 2 | |
| A | All galaxies move apart at the same speed. | They show both red-shift and blue-shift. |
| B | Distant galaxies show more red-shift. | The distant galaxies are moving apart faster than nearby ones. |
| C | Distant galaxies show more red-shift. | The distant galaxies are moving apart slower than nearby ones. |
| D | There are no galaxies that show blue-shift. | All galaxies are moving away from each other. |
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All bodies emit electromagnetic radiation.
Body R is at a higher temperature than body S.
Which statement is correct?
R emits radiation with a mean higher frequency.
R emits radiation with a mean longer wavelength.
S emits radiation with a higher intensity.
S emits radiation with a mean shorter wavelength.
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