Two football players are pushing a 60 kg blocking sled across the field at a constant speed of 1.5 m/s. the coefficient of kinetic friction between the grass and the sled is 0.30. once they stop pushing, how far will the sled slide before coming to rest?

F(friction) = u F(normal) 
so, F(friction) = (.30)(60*9.81) = 177 N 
F = ma 
so, 177 = (60)a, a = 177/60 = 2.9m/s^2 
v(final)^2 = v(initial)^2+2ax 
so, 0 = 1.5^2 + 2(-2.9)x, x = 2.25/(2*-2.9) = -.38793 the negative indicates that the direction of accel is opposite of direction of speed. 
-0.39 meters is the answer.

It is d, all the other ones say incorrect answer .