Final answer:
The force of friction opposing the motion can be found by subtracting the applied force from the total force acting on the box.
Step-by-step explanation:
The force of friction opposing the motion can be found by subtracting the applied force from the total force acting on the box. In this case, the total force is the sum of the applied force and the force of friction.
Total force = Applied force + Force of friction
Total force = 394N + (-94N)
Total force = 300N
Therefore, the force of friction opposing the motion is 300N.