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Astrophysics and cosmology

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Question 9

A distant galaxy, 2.4 × 108 light-years away from the Earth, has a measured recession speed of 5 300 km s−15\,300\text{ km s}^{-1}5300 km s−1 relative to an observer on Earth.

Which expression, based on the information above, gives the correct estimate for the age of the universe in seconds?

age=2.4×108×3.1×10165 300×103 \text{age} = \frac{2.4 \times 10^8 \times 3.1 \times 10^{16}}{5\,300 \times 10^3} age=5300×1032.4×108×3.1×1016​
age=2.4×108×9.5×10155 300×103 \text{age} = \frac{2.4 \times 10^8 \times 9.5 \times 10^{15}}{5\,300 \times 10^3} age=5300×1032.4×108×9.5×1015​
age=2.4×108×9.5×10155 300 \text{age} = \frac{2.4 \times 10^8 \times 9.5 \times 10^{15}}{5\,300} age=53002.4×108×9.5×1015​
age=2.4×108×1.5×10115 300 \text{age} = \frac{2.4 \times 10^8 \times 1.5 \times 10^{11}}{5\,300} age=53002.4×108×1.5×1011​

Astrophysics and cosmology Questions

  1. A Level
  2. /Physics
  3. /Astrophysics and cosmology