What condition must be satisfied for kinematic equations to be applicable?

For kinematic equations to be applicable, it is necessary that all vector values must be in the same line, which means they need to be co-linear. This is vital because kinematic equations rely on the linear motion of an object, where calculations of displacement, velocity, and acceleration are dependent on vectors pointing in a single direction. If vectors are not in the same line, the equations would not accurately represent the motion, as they would not account for the effects of different directions on the total distance or net velocity.

The other conditions listed do not align with the requirements for applying kinematic equations. For instance, forces being equal is unrelated to motion in a single dimension, and an object being at rest does not involve motion, which falls outside the scope of kinematic equations. Positive scalar values are not a fundamental requirement, as negative values can represent direction in motion without invalidating the applicability of these equations. Hence, the condition of having all vector values in the same line is essential to ensure the equations reflect the dynamics of the system accurately.