To determine if there is a net force on Ben, look at the forces:
Earth's gravity is pulling Ben down with a force of 400 N.
The diving board is pushing Ben up with a force of 400 N.
The forces are in opposite directions, and the forces have the same magnitude: 400 N. This means that the forces are balanced, so there is no net force on Ben.
Assume all other forces on Ben are balanced. Which statement describes the forces on Ben?
A: The forces are balanced, so there is no net force on Ben.
B: The forces are unbalanced, so there is a net force on Ben.