You push your couch a distance of 39 m across the living roo

You push your couch a distance of 3.9 m across the living room floor with a horizontal force of 180.0 N. The force of friction is 152.0 N. What is the work done by you, by the friction force, by gravity, and by the net force?

Solution

Pushing force F = 180 N

Distance S = 3.9 m

Force of friction f = 152 N

Work done by you W = FS

                               = (180x 3.9)

                               = 702 J

Work done by frictional force W \' = -fS

                                                = -152 x 3.9

                                                = - 592.8 J

Work done by gravity W \" = 0    Since gravitational force and displacment are perpendicular to each other.

Net force = F - f

              = 180 N - 152 N

              = 28 N

Work done by net force = 28 x3.9 = 109.2 J