Instructional WebSite deficient in derivation of relevant Physics Formulas
So junior was struggling big time with this physics concept called grade resistance. He found this math tutoring site created by "Professor" Laurie Morvan. She did not do the video herself, but had a guy doing it who did not explain where the grade force resistance trig equation came from! Her site did not explain how the weight of a vehicle on the inclined plane modeled by a hill was broken up in to two forces; one perpendicular and one parallel to slope or incline of the hill!!! From the force diagram that results, one can conclude that the Force(F) acting against the car going up OR down the hill is equal the sine of the angle of inclination multiplied by the weight of car, truck, UPS delivery, 18 wheeler semi truck or whatever the particular mode of transportation/conveyance that is doing the moving. One can use this equation to get the weight of vehicle given the angle and force also! The professor is no more than a preacher telling you to believe rather than rationa...