Cartoon Physics

In real physics, objects obey various rules defined by equations. Newton's 2nd law, sum of forces = mass times acceleration; applied in the direction of motion yields force of gravity (mg) in that direction (ormg*sin(angle of slope)) minus force of friction = ma; applied in the vertical direction yields mg*cos(angle of slope) minus Normal force = ma = 0 (since a is 0). The force of friction is mu (the coefficient of friction) times Normal force. Initial and final energies are equal since energy is conserved, so the sum of potential and kinetic energy is conserved, so mgh (PE, h is height, the ball starts from rest) = 1/2mv^2 (KE of moving linearly, v is velocity) +1/2Iw^2 (KE of rolling /torque, I is rotational inertia, w is omega is angular velocity) + nfd (energy of friction, where f is the force of friction, d is the distance travelled, and n is a constant). Another application of Newton's 2nd law is that the sum of torques = IA, where I is the rotational inertia and A is alpha is rotational acceleration (A= a/r, a is linear acceleration and r is radius of ball). With friction affecting the ball, the linear velocity is the same at all points of it, but the rotational velocity is to the left at the bottom, 0 at the center, and to the right at the top, so the velocities add up to Vcom (center of mass) at the middle and 2Vcom at the top.

In cartoon physics, characters can run in the air as if the ground was still exerting a normal force, only accelerating in the vertical direction once the character notices their plight.