Starting from the origin at time t = 0, with initial velocity 5$\widehat j ms
-1
, a particle moves in the x-y plane
with a constant acceleration of \left( {10\widehat i + 4\widehat j} \right)$ ms
-2
. At time t, its coordinates are (20 m, y
0
m). The
values of t and y
0
are, respectively: