Question 205983
i am on a train going north at 5 miles per hour and i start walking south at 2 miles an hour how fast am i moving ? 
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You have to specify "moving with respect to what?" 
 
You're moving 2 mph with respect to the train, and 3 mph wrt the earth, 67,500 mph wrt the sun, and ~186,000 miles per second wrt to light.