An object moves from its position when a force is applied on it. In general, force (push or pull) results in motion of an object.
The objects which do not change their position with respect to time is at the state of rest.
Let us say an object is placed on a table; it is clear that the object is stationary, meaning it is completely at rest. But, when you push or pull an object to either side of the table, it is moves out of its rest position, resulting in motion.
The objects which change their position with respect to time is at the state of motion. This change in the position can be determined by the distance measured.
A moving train, a flying bird, riding bicycle, swinging, kicking a ball, hands of a clock, blades of a fan, etc.
There are different kinds of motion. It is of three main types. They are:
Types of motion
The objects which move along a straight line are in rectilinear motion or linear motion. It is also known as translatory motion.
Motion of any vehicle on a straight road, soldiers in a parade, falling stone and runners in a \(100\)\(- metre\) race.
The motion in which the objects move along a circular path is called as circular motion.
Swirling of stone tied to a string, hands of a clock, blades of a fan, etc.
In circular motion, the distance from the centre point of the object is fixed, even when they rotate.
For instance, when you tie a thread around a stone and whirl it with your hand, the stone will be in circular motion. Here, the distance from your hand to the stone remains fixed, and the stone does not move by themselves.
The objects which are in repeated motion for equal intervals of time are in periodic motion.
Girl swinging on a swing, motion of the earth around the sun, a needle of a sewing machine, strings of guitar, the pendulum of a clock, flapping of elephant's ear, etc.
The object which moves in to and fro motion repeatedly about a fixed position is called as a pendulum.
Combination of motion
An object can undergo combinations of different types of motion.
For example, a needle of a sewing machine moves up and down continuously as long as the wheel rotates. Here, the cloth which is stitched will undergo rectilinear motion; the needle will have a periodic motion and wheel of sewing machine undergoes circular motion.
A ball rolling on the ground rotates as well as moves forward exhibiting rectilinear and rotational motion.
Motion of the earth around the sun or the motion of moon around the earth is a combination of circular as well as periodic motion.