Group $1$

Group $2$

Two groups of students each construct a sketch to predict the kinetic energy of a falling object that is subject to air resistance as it falls. Which group has produced a correct graph, and how can this selection be justified?

Group $1$ because the slope of an object's kinetic energy graph is proportional to its acceleration.

Group $1$ because the object's speed is increasing at a decreasing rate, so its kinetic energy is also increasing at a decreasing rate.

Group $2$ because it shows that the kinetic energy decreases as the magnitude of its acceleration decreases.

Group $2$ because as the object falls it will approach a terminal speed which is where the speed reaches a horizontal asymptote.