A student decides to make some extra money during a snow day. As the neighborhood kids are outside sledding, the student offers to pull the students to the top of the hill for one dollar per ride. The sled-puller noticed that it was taking more time to pull older children to the top than with the younger children even though they were pulling with the same force. Explain why some kids took longer to pull to the top of the hill then other kids despite pulling with the same force. Be sure to address the following for 2 points each:

Identify the formula used to calculate the force of each pull up the hill.
Identify what was different about the older children compared to the younger children that affected the trips up the hill
Explain how this demonstrates Newton's Second Law of Motion