If an object covers equal distance in equal interval of time, then time speed graph of an object is a straight line parallel to time axis then body is moving with a uniform speed. Non-uniform speed : If the speed of a body is changing with respect to time it is moving with a non-uniform speed.

Average speed: Average speed is defined as the uniform speed which is given by the ratio of total distance travelled by an object to the total time taken by the object.

Non-Uniform speed : If a body covers unequal distances in equal intervals of time or equal distances in unequal intervals of time,however small may be the intervals,is called Non -uniform velocity.

Constant velocity is the velocity whose direction as well as magnitude remains constant. Uniform velocity is the velocity whose magnitude(only) increases with equal intervals of time.

The uniform motion is identical to the actual speed of the object. Uniform motion covers equal distance at an equal time interval. Non-uniform motion covers unequal distance at equal time interval. In uniform motion, the distance to time graph shows a straight line.

Diagram of non-uniform circular motion: In non-uniform circular motion, the magnitude of the angular velocity changes over time. The change in direction is accounted by radial acceleration ( centripetal acceleration ), which is given by following relation: ar=v2r a r = v 2 r .

The units of uniform and non-uniform speed are same (m/s).

A body is said to have non-uniform motion if its velocity changes with time. An example of non-uniform motion is a body rotating at a constant speed. Its velocity is not constant because its direction of motion changes every instant.

A free falling object is an object that is falling under the sole influence of gravity. Any object that is being acted upon only by the force of gravity is said to be in a state of free fall.