Uniform and non-uniform (variable) velocity

Imagine a runner photographed at equal time intervals (for example every second).

• Uniform velocity: the object covers equal displacements in equal intervals of time. Its velocity has a constant magnitude and a constant direction (a straight line). In the picture, the positions are equally spaced.
• Non-uniform (variable) velocity: the object covers unequal displacements in equal intervals of time. The velocity changes in magnitude, or in direction, or both. The positions in the picture are unequally spaced.