A particle moves in the x-y plane with constant acceleration. At
time zero, the particle is at r = <5.0, 2.0> m and has
velocity v = <-4.0, 9.0> m/s. The acceleration is constant
and is given by a = <4.0, 6.0> m/s2 . (a) Find the velocity
at t = 2.0 s. (b) Find the position at t = 4.0 s. Give the
magnitude and direction of this position vector. (c) Sketch
(approximately to scale) the vector diagrams for...