Hi, I have a problem on my homework for AP Physics. I have the answer from the back but need to figure out why I am not getting the right solution. There is also an angle in the problem and I don't know what I am supposed to use it for or in what equation. The problem is: A 40.0kg wagon is towed up a hill inclined at 18.5 degrees with respect to the horizontal. The tow rope is parallel to the incline and has a tension of 140 N in it. Assume that the wagon starts from rest at the bottom of the hill and neglect friction. How fast is the wagon going after moving 80.0m up the hill? The answer for it is 7.9m/s but I was wondering if anyone could explain how and why, especially what to do with the 18.5 degree incline part. Thanks!