Gravity Components

On a ramp the weight mg splits into a part down along the slope and a part into the slope. The angle between mg and the part into the slope is the ramp angle θ:

F along = mg sin θ, F perpendicular = mg cos θ

The angle between mg and the part into the slope equals the ramp angle θ.

Nothing accelerates into the slope, so N = mg cos θ. On a 30° ramp a 10 kg box is pulled down the slope with 49 N, and N is about 84.9 N instead of 98 N.