Question

A 1.2 kg block of mass is placed on an inclined plane that has a slope of 30° with respect to the horizontal, and the block of mass is released. A friction force Fk = 2.0 N acts on the block as it slides down the incline. Find the acceleration of the block down the incline

Answer 1

this how the FBD will be

now, write the equations of motion from this and solve for acceleration a.
note that, we have equilibrium in y direction (perpendicular to the incline) and motion in x direction (parallel to the incline).