A block of mass m slides on a rough horizontal surface with coefficient of kinetic friction μ. A force F is applied at angle θ below the horizontal. Its acceleration is:
Options

Question

A block of mass m slides on a rough horizontal surface with coefficient of kinetic friction μ. A force F is applied at angle θ below the horizontal. Its acceleration is:

G1 Physics · Accepted Answer

The downward component F sinθ increases normal reaction: N = mg + F sinθ. Kinetic friction = μN = μ(mg + F sinθ). Horizontal net force = F cosθ - μ(mg + F sinθ). Therefore a = [F cosθ - μ(mg + F sinθ)]/m.