Why do linear accelerated motion equations work for this circular motion question?
Using “vf^2 = vi^2 + 2*a*s” is BAD PHYSICS to answer the question about the skateboarder entering the circular ramp. His tangential acceleration is most certainly NOT constant, not even close to equaling g (except at the locally vertical end of the ramp), AND the ramp arc-length is NOT equal to the distance he rose above the base of the ramp (except approximately when the ramp is locally vertical). The REAL method you MUST use (if you were in my class) to answer the question is with energy considerations. By using energy considerations, you first assume that there is no NET non-conservative force acting on him. What is a non-conservative force? A force for which you do not track the energy associated with work done by it. Examples are kinetic friction and human forces. When only conservative forces (and forces of constraint) act on a target object, the work done by them is INDEPENDENT of the path, it only depends on the initial and final states. First find his initial kinetic energy: K
