Answer:
The net force acting on the person is

Step-by-step explanation:
If we want to calculate the net force acting on the person we need to sum all forces that act over the person.
There are two forces acting on the person. Its weight and the total drag force.
The total drag force has a value of 720 N and its sense is upward.
We can calculate the weight force as

Where W is the weight force
Where m is the mass of the person
And where g is the acceleration due to gravity
We are going to use

If we calculate W ⇒

If we vectorial sum the total drag force and the weight force :

We used a reference system where we consider the positive forces pointing upward (that is why we add a negative to the force W).
The net force acting on the person is
