Answer:
B.0 N
Explanation:
Based on the description of the free-body diagram, there are only two forces acting on the child sitting on the seat:
- The force of gravity, Fg=-100 N, in the downward direction
- The normal reaction of the chair on the child, Fn=100 N, in the upward direction
The two forces have same magnitude but in opposite directions, so the net force (resultant of the two forces) is zero:
[tex]F_{net}=F_n+F_g=100 N-100 N=0 N[/tex]
