Final answer:
The normal force on the child's feet when the rope's tension is 220 N can only be calculated if the child's weight is known, which is not provided in the question. Without the child's weight, we cannot determine the exact value of the normal force.
Step-by-step explanation:
The student asks about the normal force exerted on the child's feet when the tension in the rope is reduced to 220 N. To find the normal force, we must realize that the normal force is the force exerted by the ground on the child, countering the gravitational pull. As the tension in the rope is 220 N, this is the force that is pulling the child upward, partially counteracting gravity. Assuming the child is at rest, the combined normal force and the tension must equal the gravitational force. Therefore, if we know the child's weight (gravitational force), we can find the normal force by subtracting the tension in the rope from it.
However, the problem does not reveal the child's weight, so we cannot calculate the exact value of the normal force without additional information. The students are encouraged to provide the weight of the child to proceed with the calculation. If the weight of the child equals or is less than 220 N, then there would be no normal force since the rope's tension alone supports the child. If the child's weight is greater than 220 N then the normal force would be the difference between the child's weight and 220 N.
We cannot determine the exact value of the normal force and therefore cannot identify the correct multiple-choice option without this crucial piece of data.