A particle moves from x-y point (1,1) to point (2,4) to point (3,9) in time
2/sqr(5) seconds (.8944 seconds). It is not at rest at point (1,1).
In what direction is the net force on it?
What is the average acceleration in the x direction and y direction?

Question

A particle moves from x-y point (1,1) to point (2,4) to point (3,9) in time 
2/sqr(5) seconds (.8944 seconds). It is not at rest at point (1,1).
In what direction is the net force on it?
What is the average acceleration in the x direction and y direction?

anonymous · Answer

you might want to resolve the points to vectors before attempting to solve it to simplify the question.
$\vec v =\vec u + \vec a t$
$\vec S_f = \vec S_i +\vec u t + \frac{1}{2} \vec a t^2$
and $\vec F=m \vec a$
sub the points  and the time in to solve for a