Answer:
1. When a spring scale is used to do work pulling a cart to the top of an incline, the elastic energy stored in the spring is converted into gravitational potential energy, since the top of an incline has a certain height.
2. The roller coaster get its gravitational potential energy from the kinetic energy it carries when it moves with a certain velocity.
3. Truckers use a ramp because it is easier to load a truck with less applied force. Although the work required is the same, without the ramp the force that they should apply is much greater, hence more difficult.

h is greater than (d x cos(Θ)), hence F2 is smaller than F1.