# NCERT Chapter Summary: Motion

Motion is a **change of position**. It can be described in terms of the distance moved or the displacement. The motion of an object could be uniform or non-uniform depending on whether its velocity is constant or changing.

The **speed** of an object is the distance covered per unit time, and **velocity** is the displacement per unit time.

The **acceleration** of an object is the change in velocity per unit time. Uniform and non-uniform motions of objects can be shown through graphs.

The motion of an object moving at uniform acceleration can be described with the help of the following equations:

- v = u + at
- s = ut + ½at
^{2} - 2as = v
^{2}- u^{2}

where u is initial velocity of the object, which moves with uniform acceleration a for time t, v is its final velocity and s is the distance it traveled in time t.

If an object moves in a circular path with uniform speed, its motion is called **uniform circular motion**.