1.1. Hydrogen is an element of particular interest to astronomers, as it can emit visible light waves.

A lot of useful information can be obtained by measuring the wavelength of the emitted light from the hydrogen in distant galaxies and comparing them to a laboratory sample of hydrogen. Some sample data is shown in the table.

The detected wavelengths from the galaxies are different from the detected wavelength from the laboratory sample because of the Doppler effect.

Galaxy X and galaxy Y are both moving relative to Earth. 

Compare the motions of galaxy X and galaxy Y relative to Earth.

1.2. Use data from the table to calculate the speed of galaxy Y relative to Earth. 

Speed of light, c = 3.0 × 10⁸ m/s

speed of galaxy Y = ................................... m/s