Answer:
3.69 N
Explanation:
Draw a free body diagram. There are four forces acting on the object:
Weight force W pulling straight down.
Normal force N pushing perpendicular to the inclined plane.
Friction force f pushing down the inclined plane.
Applied force P pushing up the inclined plane.
Sum of forces in the perpendicular direction:
∑F = ma
N − W cos θ = 0
N = W cos θ
Friction force is normal force times the coefficient of friction:
f = Nμ
f = Wμ cos θ
Plug in values:
f = (15.0 N) (0.300) cos 35.0°
f = 3.69 N
