Posted by luc on Saturday, October 10, 2009 at 1:03am.
A 40.0 kg wagon is towed up a hill inclined at 17.9° with respect to the horizontal. The tow rope is parallel to the incline and has a tension of 140 N. Assume that the wagon starts from rest at the bottom of the hill, and neglect friction. How fast is the wagon going after moving 75 m up the hill?

physics  bobpursley, Saturday, October 10, 2009 at 9:55am
The central thing is to find the net force, up, then the acceleration, then the distance.
net force up=14040g*sinTheta
acceleration= net force up/mass
Work done on gravity=mg*75*sinTheta
Work done by pulling=140*75
Kinetic energy=1/2 m v^2
so
140*75=1/2 mv^2+mg*75*sinTheta
and you solve for v.