1.1. Extended tier only

Explain what type of radiation the CMBR will eventually change into over the next billion years.

1.2. Extended tier only

Scientists measure the wavelength of the radio waves from galaxy A travelling at 260 km/hr away from Earth to be 63.2 m. Sometime later, the wavelength is measured to be 63.4 m.

The wavelength of the radio waves from galaxy B is initially measured to be 63.4 m and at the same time later, measured to be 63.8 m.

Calculate the velocity of galaxy B.

velocity of galaxy B  = ...................................... m/s 

1.3. Extended tier only

By measuring the redshift of galaxies, Hubble was able to calculate the speed at which they move away from the Earth. Hubble was also able to calculate the distance of these galaxies from the Earth.

The graph in Fig 1.1 shows some of the data calculated by Hubble.

Fig 1.1

The graph in Fig 1.1 was used to calculate the most up-to-date value of the Hubble constant, H₀. 

Megaparsecs are a unit for large distances commonly used in Astronomy and Cosmology. 1 megaparsec = 3.1 × 10²² m.

 Calculate H₀ in km/s megaparsec.

1.4. Extended tier only

Show that H₀ is roughly equal to 2.0 × 10^–18 per second.