A couch of mass 245 kg is being pushed across the floor with an applied force of 4300 N.

Question

The coefficient of kinetic friction between the co? 

 

Update : couch and the floor is 0.47. Draw the free body diagram. find normal force on couch and find the acceleration

Update 2: acceleration of couch and please answer this quick I have a lot to do after this and who ever gets correct and answers it first or second but has detailed answer, they will get best answer

 

Answer 1

Mass of the couch is 245 kg .

Force applied on the couch is 4300 N .

The coefficient of kinetic friction between the couch and the floor μ is 0.47 .

The free body diagram is  

In the vertical axes forces are equal and opposite as there is no vertical acceleration.

F_N = -F_g 

F_N = mg = (245)(9.8)

F_N = 2401 N 

So the normal force is F_N = 2401 N .

The  the frictional force is F_f = μ F_N .

The net force F = force applied - frictional force 

                         F = 4300 - (0.47)(2401)

                   F = 4300 -1128.47

                         F  = 3171.53

So the net force = F = ma = 3171.53

  ma = 3171.53

a = 3171.53 / m

a = 3171.53 / 245

a = 12.94 m/s² .

So the acceleration of the body is 12.94 m/s² .