The acceleration of a particle at any instant moving along a circular path in a direction normal to the tangent at that instant and directed towards the centre of the circular path is known as normal component of the acceleration or normal acceleration. It is also called radial or centripetal acceleration.

Linear acceleration is defined as the rate of change of linear velocity of a body with respect to the time.

The speed is traveled distance (60 miles) divided by traveled time (4pm – 2pm = 2hours):

The displacement of a body is a vector quantity, as it has both magnitude and direction. Linear displacement may, therefore, be represented graphically by a straight line.

When the motion of a body is confined to only one plane, the motion is said to be plane motion. The plane motion may be either rectilinear or curvilinear.

If the displacement is along a circular path, then the direction of linear velocity at any instant is along the tangent at that point.

Angular velocity is defined as the rate of change of angular displacement with respect to time. It is usually expressed by a Greek letter ω (omega).

Rectilinear Motion is the simplest type of motion and is along a straight line path. Such a motion is also known as translatory motion.

Curvilinear Motion is the motion along a curved path. Such a motion, when confined to one plane, is called plane curvilinear motion.

The acceleration of a particle at any instant moving along a circular path in a direction tangential to that instant, is known as tangential component of acceleration or tangential acceleration.