a quasar is moving away from earth with a speed 0f 0.850c. It emits a proton that eventually reaches earth with a speed of 0.519c relative to the earth. How fast is the proton moving relative to the QUASAR.
The Attempt at a Solution
u = u' + v / 1 + u'(v) / c^2
u = 0.578c relative to earth.
How do I go about getting an answer relative to the object emitting the proton?
thanks for help. appreciate it