Final answer:
The correct answer is (d) Both force applied by the person and tension, as both contribute to the net force acting on the load via the rope. Tension is the force transmitted through the rope, and the applied force is provided by the person pulling on the rope.
Step-by-step explanation:
When calculating the number of forces acting on a load being pulled by a rope, you should consider the force applied by the person along with the tension in the rope. The tension is the force along the length of the rope that arises when it is pulled at both ends. As the person applies a force, the rope transmits this force via tension to the load. Therefore, the correct answer would be (d) Both force applied by the person and tension.
The concept of tension is fundamental because a rope can only pull objects; it cannot push. Tension in a rope can be visualized with free-body diagrams, where forces are shown as vectors, indicating the direction and magnitude of the forces. When the system is at rest or moving at constant velocity, the tension is equal throughout the rope and is equal to the weight of the load if the load is not accelerating vertically. If the load accelerates, the tension must be greater than the load's weight to produce the upward acceleration. Conversely, if the load is accelerating downward, the tension is less than the weight of the load.