OK..HER'S THE DEAL..
u've got to find the speed,v, when the force is removed..:
v=u+at
v=2.357x2= 4.714 m/s
then u have to find the new acceleration:
-mgsin20-uR=ma..
-mgsin20-umgcos20=ma (divide by m)
-9.8sin20-0.466x9.8xcos20=-7.643 (the -ve sign is due to opp direction)
now:
v^2=u^2n+2as..
v=0
u=4.714
a=-7.643
therefore:
s= -(4.714)^2/2x-7.643
s= 1.45 m...hope that helped