Velocity-time graphs show how the velocity (or speed) of a moving object changes with time. These graphs also show if the object is moving at a constant speed or accelerating, decelerating, or ...

When an object moves at constant velocity V, at time t, it is at distance D(t) away from the eye, and subtends a visual angle of θ(t). Time course of four optical variables, τ (and 1/τ), θ, ρ ...

Acceleration and velocity Newton's second law says that when a constant force acts on a massive body, it causes it to accelerate, i.e., to change its velocity, at a constant rate.