Newton's Second Law: a 50

Multiple Choice

Newton's second law: A 50.0-N box is sliding on a rough horizontal floor, and the only horizontal force acting on it is friction. You observe that at one instant the box is sliding to the right at 1.75 m/s and that it stops in 2.25 s with uniform acceleration. What magnitude force does friction exert on this box?

A) 3.97 N
B) 8.93 N
C) 38.9 N
D) 50.0 N
E) 490 N