Marsha is pushing down and to the right on a 21-kg box at an angle of 30 below horizontal. The box slides at constant velocity across a carpet whose coefficient of kinetic friction with the box is 0.70.
1. Decide the magnitude of the force exerted by Marsha on the box.
2. Decide the magnitude of the normal force exerted by the surface on the box.
3. Determine the magnitude of the friction force exerted with the surface on the box.