To determine the force needed to jump, one must consider both the net acceleration and the gravitational force acting on the jumper. The net acceleration can be calculated using the final velocity and time in contact with the ground, leading to the conclusion that the force exerted while jumping is related to the normal force. The discussion clarifies that the question is focused on the force the jumper must exert against the ground, which corresponds to the normal reaction force. The calculations provided show how to derive the necessary speed and acceleration for a jump of 2.0 meters, ultimately leading to the determination of the required push-off force. Understanding these dynamics is crucial for accurately assessing the physics of jumping.