A spacecraft is coasting in deep space with a uniform velocity of 200m/s. Its engines are switched off at t=0. Which option best describes its motion at t=600s, assuming no other forces act on it?
a) It gradually slows down and eventually comes to rest.
b) It will have travelled 1.2×105m from its starting point but not necessarily at the same speed.
c) It continues to move at 200m/s in the same straight line.
d) It speeds up continuously because no forces oppose its motion.