Hi, I am doing the same correspondence course and am at this question. I don't understand why Fn would not be equal to -Fg. The wagon is being pulled horizontally so why would the Fn be different?
sorry for digging up this old thread but I am taking a correspondence course with this same question in it...there really isn't many example questions in this course for me to properly grasp this. Any chance someone could point me to a place to get more practice questions like the one above?