In: Physics
A block of mass m1=4.00 kg moves on the surface of a horizontal table. The coefficient of kinetic friction between the table top and m1 is equal to 0.350. Block 2 of mass m2=2.00 kg is tied to m1 via a string that passes over a frictionless, massless pulley. The two blocks start from rest and m2drops by a distance L=1.75 m to the floor.
Calculate the net work Wnet done by all the forces acting on the system

From the diagram above


The equation of motion for m1 is

The equation of motion for m2 is

From the above two equations




Now,
The displacement in the system is 1.75 m.
So, the work done by the frictional force on the system is

And the work done by the gravity is

And the work done by the tension on m1 is

The work done by tension on m2 is

So finally the net work-done on the system is

