What is the answer?

Question

1. a worker pushes in 50.0 kg box on a level floor at constamt velocity and moves a distance of 10.0 m. If a person pushes it with a force of 850N, what must be the magnitude and the direction of frictional force on the surfac

Answer 1

Because the worker is pushing at constant velocity, the net horizontal force is zero. That means the pushing force equals the friction force opposing it in the horizontal direction.So the magnitude of the frictional force is 850 N in the opposite direction of the push.