a man pulls a 500 N block up a plane inclined 30 degrees with the horizontal with a force 300 N parallel to the plane. what net force tends to pull the block up the plane?
300 - 500 sin 30 = 50 N
The 500 sin 30 is the component of the weight down the plane.
There would in most cases also be a friction force opposite to the direction of motion. It would further reduce the net force up the plane.