s(t) = -(1/2)at^2+v_0(t)+s_0
s(t) is distance traveled from starting point.
"a" is the acceleration.
v_0 is initial velocity.
s_0 is initial starting distance traveled (which is zero here).
s(t) = - (1/2)*11*t^2+50*t
s(t) = -11*t^2+50t
Use this to solve all your problems.