"...with acceleration due to gravity g... A point-like unit mass slides frictionlessly over the surface under the action of gravity." If you make up funny phys

"...with acceleration due to gravity g... A point-like unit mass slides frictionlessly over the surface under the action of gravity." If you make up funny physics problems that don't look like the real world, then the math works out funny. What about heat, light, the motion of the larger entire system? There are a lot of forces they are just hand waving away. I think it's disingenuous to hand wave away much of the complexity of the real world and still expect your algebra problem to not be overly simplistic.