David pushes on a box with a force of 11 Newtons to the right, and his friend pushes on the box with a force of 8 Newtons to the left. What is the net force acting on the box?

Water at p1 = 20 bar, t1 = 400oc enters a turbine operating at steady state and exits at p2 = 1.5 bar, t2 = 240oc. the water mass flow rate is 4000 kg/hour. stray heat transfer and kinetic and potential energy effects are negligible. determine the power produced by the turbine, in kw, and the rate of entropy production in the turbine, in kw/k.