At what relative speed must a clock move if it is observed to run at 10 the rate of the observer's clock? if an astronaut could travel a v 0980c for at time of t -12.0 hr as measured on earth, how much time would the astronauts measure for the trip? what would the distance traveled be according to an observer on earth? what would the distance traveled be according to the astronaut? an object has mass of 1.0 kg and is moving at 0.850c. a. what is its classical momentum? b. what is its relativistic momentum? c. what is its rest energy? d. what is its classical kinetic energy? e. what is its relativistic kinetic energy?