Motion is the change in the position of an object with respect to its surroundings. It can be described in terms of the distance moved by an object or its displacement. The rate of motion can be determined by measuring the distance travelled in unit time. This is referred to as speed. It makes more sense if we mention the direction of motion along with its speed to define rate of motion. This quantity is called velocity, which is given by the displacement per unit time. Moreover, the rate of change of velocity with time is known as acceleration.
An object can either move in uniform or non-uniform motion. If the velocity of the object is constant with time, then its motion is said to be uniform. However, if its velocity is changing with time, then its motion is non-uniform. Both these motions can be represented through different graphs – distance-time graph or velocity-time graph.
Motion of an object along a straight line with uniform acceleration can be described by a set of equations known as equations of motion. These equations relate its velocity, acceleration and distance covered by it in a certain time interval.
Motion of an object along a circular path with uniform speed, called uniform circular motion, is an accelerated motion as the direction of velocity changes continuously.