Part F is a standard Force diagram along an inclined surface:
You are calculating the component of the force parallel to (i.e. along) the surface
Part G, H and I seem similar to above. For example in Part H you literally model the hill as a triangle and you have a slope that you walk up along. For Part I, you can see the force diagrams here:
For Part J, you need to decompose, not forces, but velocities in a similar manner as before.