The image shows a scenario where four forces are applied horizontally to a door, and the goal is to determine the net torque relative to its axis.

To solve this, we need to consider the torque produced by each of the four forces. Torque is given by the formula:

$\tau = F \cdot r \cdot \sin(\theta)$

where:

• $\tau$ is the torque,
• $F$ is the force,
• $r$ is the distance from the axis of rotation (in this case, the width $l$ of the door),
• $\theta$ is the angle between the force and the arm.

In this case:

• The forces are applied in horizontal directions.
• Each force produces a torque depending on whether it's acting clockwise or counterclockwise.

To determine the net torque, we would calculate the individual torques for each force and then sum them, considering their direction (clockwise or counterclockwise). Based on symmetry and typical configurations of such problems, we should expect the forces to create a net torque of around 2.0 $F \cdot l$.

Thus, the closest option for the net torque on the door relative to its axis is 2.0 F·l.

Let me know if you need further clarification or any more details on this! Would you like to discuss the torque calculations or any other related concepts?

Here are some related questions you might find interesting:

1. What is the general formula for calculating torque?
2. How do different forces applied at various points on a door affect the net torque?
3. What is the impact of the direction of force on the torque value?
4. How can torque be calculated in situations involving multiple forces?
5. How does the point of application of force on a door affect the rotational behavior?

Tip: When multiple forces are applied at different points, you can calculate the torque from each force separately and then sum them, keeping track of their directions (clockwise or counterclockwise).