D. Friction
For added realism in motion game, a frictional component
is essential for monitoring the acceleration and
deceleration of objects. This component can be
implemented in various ways depending on the equation
being used. A simple example would be the velocity
equation v = u + at which is responsible for the linear
increase of speed with respect to time until a maximum
speed is reached. However for applications such as card
or strategy game, this component might not be essential.