This is my question

N = 470 [N]

Explanation:

The normal force is defined as the reaction exerted by the surface where the body is located in the opposite direction to the weight component.

It can be easily calculated by means of the product of mass by gravitational acceleration.

N = m*g

where:

N = normal force [N] (units of Joules)

m = mass = 47 [kg]

g = gravity acceleration = 10 [N]

N = 47*10

N = 470 [N]

in physics zero. in muscle fatigue could be high

if the person is shown to have +90n, then ans is -10n.

if the person is shown to have -90n, then ans is +10n.