Final answer:
The average power delivered by the child is approximately 17 W.
Step-by-step explanation:
To calculate the average power delivered by the child, we need to use the formula P = W/t, where P is power, W is work, and t is time. Work is calculated by multiplying the force applied by the distance moved, so W = F * d. In this case, the force is 75 N and the distance moved is 42 m. Substituting these values into the formula, we get W = 75 N * 42 m = 3150 N * m. The time taken to move this distance is 3.1 minutes, which is equal to 3.1 * 60 = 186 seconds. Finally, we can calculate the average power by dividing work by time: P = 3150 N * m / 186 s = 16.94 W. Therefore, the average power delivered by the child is approximately 17 W.