# On the motion of a particle [closed]

A particle starts from the origin at $$t = 0$$ under a variable acceleration $$\alpha$$, it stops at $$t = 1$$ at $$(0,1)$$, provided that the motion takes place along the x-axis. Show that:

i) The value of $$\alpha$$ cannot be positive for all $$t \in [0,1]$$

ii) $$|\alpha| \geq 4$$ for some points (or points) in it's path.

While the first part is obvious (as the particle must decelerate for the velocity to come to zero), I couldn't prove the second part.