Question

A couch of mass 210 kg is being pushed across the floor with an applied force of 4100 N. The coefficient of kinetic friction between the couch and the floor is 0.38 Find the normal force on the couch. Find the acceleration of the couch

Answer 1

Let us use the formula for Newton's Second Law of Motion:

Net force = Mass*Acceleration
Net force = Applied Force - μ*Normal Force
where μ is the coefficient of kinetic friction

Normal Force = Force due to gravity = mass*gravity
Normal Force = (210 kg)(9.81 m/s²) = 2,060.1 N

Then,
Net force = 4100 - 0.38*2060.1 = 3317.162 N

3317.162 N = (210 kg)(a)
Solving for acceleration,
a = 15.796 m/s²