What name is given to objects that orbit a planet? A space telescope uses microwaves to communicate with the Earth - AQA - GCSE Physics - Question 6 - 2023 - Paper 2

To calculate the frequency (

f) of the microwave, we can use the formula:

$f = \frac{v}{\lambda}$

where:

• v is the speed of the waves (3.0 × 10^8 m/s)
• λ (lambda) is the wavelength (12.5 cm = 0.125 m)

Substituting the values, we have:

$f = \frac{3.0 \times 10^8 \, \text{m/s}}{0.125 \, \text{m}} = 2.4 \times 10^9 \, \text{Hz}$

Thus, the frequency of the microwave in standard form is 2.4 × 10^9 Hz.

From Figure 16, we can observe:

• Galaxy A has a greater red shift compared to Galaxy B.
• This implies that Galaxy A is moving away from us at a faster speed than Galaxy B.
• Since Galaxy A is also further away from us, we can conclude that both galaxies A and B are receding from the Earth, consistent with the expansion of the universe.