A Box That Weighs 300 N Is Pulled by a Rope

Multiple Choice

A box that weighs 300 N is pulled by a rope across a level surface with a constant velocity. The rope makes an angle of 30.0 degrees above the horizontal, and the tension in the rope is 100 N. What is the magnitude of the normal force from the floor on the box?

A) 86 N
B) 300 N
C) 50 N
D) 250 N
E) 0 N