Answer:
B: 86 N
Explanation:
There are four forces acting on the couch. Weight pulling down, normal force pushing up, your applied force to the right, and friction opposing you to the left.
In the y-direction:
∑F = ma
N - W = 0
N = W = mg
In the x-direction:
Fnet = P - Fᵣ
Fnet = P - Nμ
Fnet = P - mgμ
Given P = 650 N, m = 71 kg, g = 9.8 m/s², and μ = 0.81:
Fnet = 650 - (71)(9.81)(0.81)
Fnet = 86 N
