A Box Is Moved 10 M Across a Smooth Floor

Multiple Choice

A box is moved 10 m across a smooth floor by a force F making a downward angle with the floor, so that there is effectively a 4 N force acting parallel to the floor in the direction of motion and a 3 N force acting perpendicular to the floor. The force F acts for 20 seconds. The impulse delivered to the box by the floor during this process has magnitude

A) 100 Ns.
B) 80 Ns.
C) 60 Ns.
D) zero.
E) Can't tell without knowing the weight of the box.