The question involves understanding the forces acting on a box being pushed across a table. Specifically, we need to identify which force is represented by [tex]\(-7 \, \text{N}\)[/tex].
We know that forces can be either positive or negative. A negative force typically indicates that the force is acting in the opposite direction to the motion or intended movement.
Let's analyze the forces one by one:
1. Force of Friction: Frictional force always opposes the motion of an object. If the box is being pushed forward, the frictional force would act in the backward direction, opposing the motion. Therefore, friction could logically be represented by a negative value.
2. Normal Force: This is the supporting force exerted perpendicular to the surface in contact. For this scenario, it acts upward perpendicular to the table's surface. It does not oppose the horizontal motion directly and would be a positive force acting upwards.
3. Force of Gravity: Gravity pulls the box downward towards the Earth. This force would also not be represented as a horizontal opposing force. It acts vertically downward, so it isn't relevant to the horizontal motion directly.
4. Push Force: This is the force exerted by the person pushing the box. It acts in the direction of the intended motion, meaning it would be a positive force in the direction the box is being pushed.
Given this information, the only force that opposes the horizontal motion (and thus can be negative) is the force of friction.
Therefore, the force represented by [tex]\(-7 \, \text{N}\)[/tex] is the force of friction.
