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The Big Bang theory is one theory for the origin of the Universe - Edexcel - GCSE Physics - Question 4 - 2021 - Paper 1
Question 4
The Big Bang theory is one theory for the origin of the Universe. The Big Bang theory suggests: the Universe had a beginning the Universe is still expanding (a) W... show full transcript
Worked Solution & Example Answer:The Big Bang theory is one theory for the origin of the Universe - Edexcel - GCSE Physics - Question 4 - 2021 - Paper 1
Step 1
Step 2
Describe how light from distant galaxies shows that the Universe is still expanding.
Answer
Light from distant galaxies exhibits a redshift, which means that the wavelengths of the light are stretched. This phenomenon occurs because the galaxies are moving away from us, thus indicating that the Universe is expanding.
Step 3
Give one similarity and one difference when comparing the Big Bang theory with the Steady State theory.
Answer
Similarity: Both theories propose an expanding Universe.
Difference: The Big Bang theory suggests that the Universe had a beginning, whereas the Steady State theory posits that the Universe has no beginning and maintains a constant density through the continual creation of new matter.
Step 4
Step 5
Calculate the gradient of the line shown in Figure 4.
Answer
To calculate the gradient ( rac{ ext{change in velocity}}{ ext{change in distance}}), the evaluations can be done as follows:
Using two points from the graph: (0,0) to (15,1050) Gradient = rac{1050 - 0}{15 - 0} = 70 ext{ km/s per Mpc}.
Step 6
Explain why the gradient of the line in Figure 4 can only provide an estimate of the age of the Universe.
Answer
The gradient indicates the rate at which the galaxies are moving away. However, it is an estimate because it is based on current observations that could change over time, and it does not account for variations in the rate of expansion that may have occurred throughout the Universe's history.