What is happening between points

a-b? point a and point b are examples of potential energy, there is not energy transformation taking place here.

point a is demonstrating kinetic energy, as the roller coaster moves downhill the kinetic energy is transformed into potential energy.

point a and point b are examples of kinetic energy, there is not energy transformation taking place here.

point a is demonstrating potential energy, the potential energy is then transformed into kinetic energy as the coaster moves downhill.

Aperson gives a shopping cart an initial push along a horizontal floor to get it moving, and then lets go. the cart travels forward along the floor, gradually slowing as it moves. consider the horizontal force(s) on the cart while it is moving forward and slowing. which of the following statements is correct? (a) both a forward and a backward force are acting on the cart, but the forward force is larger. (b) only a forward force is acting which diminishes with time. (c) both a forward and a backward force are acting on the cart, but the backward force is larger. (d) only a backward force is acting, no forward force.