Basic principles of relativity
If an object is travelling west at a constant 6m/s and a man is travelling east at a constant 10m/s in a car what speed does the object appear to be moving at? Assuming that the observer in this context is the man meaning that he is perceiving the objects speed relative to his own position.
The answer is 16.
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1 solution
Since the man is travelling east a constant 10m/s and the object is travelling west at a constant 6m/s that means both are travelling away from each other. Therefore from the observers perspective it appears that the object is travelling 16m/s west because his speed of 10m/s plus the objects speed of 6m/s equals 16m/s. Relative motion is one of the fundamental ideas of Einstein's theory of relativity.