Motion in a plane

A particle starts from origin
at t = 0 with a velocity 5.0 î m/s and moves
in x-y plane under action of a force which
produces a constant acceleration of
(3.0i
ɵ+2.0j
ɵ
) m/s 2
. (a) What is the
y-coordinate of the particle at the instant
its x-coordinate is 84 m ? (b) What is the
speed of the particle at this time ?