A 18-Kg Block Is Projected Up a Rough 10 $\degree$ Inclined Plane

Multiple Choice

A 1.8-kg block is projected up a rough 10 $\degree$ inclined plane.As the block slides up the incline,its acceleration is 3.8 m/s² down the incline.What is the magnitude of the force of friction acting on the block?

A) 5.0 N
B) 3.8 N
C) 4.2 N
D) 4.6 N
E) 6.5 N