Two people push on a crate. Person 1 pushes in the positive X direction with a force of 25N. The second person pushes in the negative X direction at an angle of 15 degrees below the horizontal with a magnitude of 18.5N the box moves with uniform velocity. What is the force of friction between the box and floor?

1 answer

break up the negative x direction into components:
Vertical: 18.5sin15 upward
horizontal: 18.5cos15 in neg x direction

25-18.6cos15-friction=mass*acceleration=0
solve for friction force.