The upward normal force exerted by the floor is 710 N on an elevator passenger who weighs 720 N . You may want to review (Pages 107 - 110) . For related problem-solving tips and strategies, you may want to view a Video Tutor Solution of Weighing yourself in an elevator. Part A What is the reaction force to the upward normal force exerted by the floor

If the person is to remain the floor the reaction force will be equal to the normal force exerted by the floor.

F(normal) - F(reaction) = 0

That means the person is not moving with respect to the elevator.

Expanding the applied forces we have:

Fw - Fn = 720 - 710 = 10 N   where the positive direction is chosen as down

Fw is the weight of the person and Fn the force exerted on the person by the elevator,

The acceleration of the person the becomes F = m a = m * 10 N and will be downward agreeing with our choice of coordinate axes.

he kicked it 10 feet straight up into the air? i think this works.

none, its a machine