Hint:
read up about Newton's first law, for example, at the following link:
http://www.physicsclassroom.com/class/newtlaws/Lesson-1/Newton-s-First-Law
suppose that an astronaut throws a rock into outer space at a location far from significant influences of gravity and air resistance. One would expect the rock would
A. eventually stop because all objects "lose steam"
B. eventually stops as its inertia becomes used up
C. Continue in motion with the same speed an direction
D. either a,b,c depending on whether or not the astronaut continues to push it
2 answers
Because it is acted upon force