The normal force(the force pushing up from a flat surface) is equal to the force of gravity (the force pushing down on the object) at 5N so they cancel each other out. The other two forces are going in opposite directions, one positive and one negative. Subtracting 10N-5N would give you the amount of force that is not canceled (5N) in the direction of the biggest force (to the left)
The answer is evolutionary!
I hope I was able to help. :)
Answer:
D. Allow him to go around obstacles too difficult.
