6. Space physics
A section of Physics, 0625
Listing 10 of 156 questions
A galaxy is approximately 1.2 × 1026 m from the Earth. Scientists observe light from the distant galaxy. The wavelength of the observed light is longer than the wavelength of the light emitted from the galaxy. State the name of this effect. State the current estimate for the Hubble constant H0. H0 = Calculate the speed at which the galaxy is moving away from the Earth. speed = Scientists have measured the speeds at which distant galaxies are moving away from the Earth and their distances from the Earth. These measurements suggest that all the Universe was once at a single point. Explain why.
0625_s24_qp_43
THEORY
2024
Paper 4, Variant 3
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The Milky Way is one of many billions of galaxies. Each galaxy contains many billions of stable stars. Stable stars transfer energy into space by emitting electromagnetic radiation from their surfaces. Describe what happens in the core of a stable star to release energy that is eventually transferred into space. On the Earth, light from a distant galaxy is observed and analysed by astronomers. This information is used to determine the speed at which the galaxy is moving away from the Earth. Describe how the observed light is different from when it was emitted. State the quantity that astronomers use to determine the speed at which the galaxy is moving away. The Hubble constant H0 is equal to 2.2 × 10–18 per second. Calculate the distance from the Earth of a galaxy that is moving away at a speed of 1.3 × 107 m / s. distance = Calculate an estimate for the age of the Universe. Give your answer in years. age of the Universe = years
0625_w23_qp_41
THEORY
2023
Paper 4, Variant 1
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The Milky Way is the galaxy in which the Solar System is located. State what a galaxy is. The Milky Way has a diameter that is approximately equal to 100 000 light-years. Determine this distance in kilometres . distance = km Astronomers determine the speed and distance from the Earth of a far galaxy that is moving away from the Earth. State one observation that allows the speed at which a galaxy is moving away to be determined. State one different observation that is used to determine the distance to a far galaxy. State how the speeds of galaxies and their distances from the Earth are related. The best estimate for the Hubble constant H0 is 2.2 × 10–18 per second. Use this value to calculate an estimate for the age of the Universe. age of the Universe = s
0625_w24_qp_41
THEORY
2024
Paper 4, Variant 1
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Questions Discovered
156