Question

At time t = 0, constant force begins to act on a rock moving through deep space in the +x direction.
For time t > 0, which are possible functions x(t) for the rock’s position?

(1) x = 4t – 3
(2) x = –4t^2 + 6t – 3
(3) x = 4t^2 + 6t – 3

Thank you.