A distant galaxy emits light that has a wavelength of 655.6 nm. On earth, the wavelength of this light is measured to be 661.9 nm. (a) Decide whether this galaxy is approaching or receding from the earth. (b) Find the speed of the galaxy relative to the earth. (Give you answer to 4 significant digits. Use 2.998 × 108 m/s as the speed of light.)

A distant galaxy emits light that has a wavelength of 655.6 nm. On earth, the wavelength of this light is measured to be 661.9 nm. (a) Decide whether this galaxy is approaching or receding from the earth. (b) Find the speed of the galaxy relative to the earth. (Give you answer to 4 significant digits. Use 2.998 × 108 m/s as the speed of light.)