Answer:
fr = 7.84 N
Explanation:
To solve this exercise we must use Newton's second law, the case of translational equilibrium
F -fr = 0
F = fr
where F is the applied force and fr the friction force
for the Y axis
N -W =
N = W
N = m g
the friction force has the equation
fr = μ N
fr = μ m g
in this case they indicate the two materials that are in contact with wood on wood, so when reviewing the tables the coefficient of static friction is μ=0.4
let's calculate
fr = 0.4 2.0 9.8
fr = 7.84 N
