The ancient Greek philosopher Aristotle had the view that all objects have a natural place like heavy objects wanted to be at rest on the Earth and the light objects like smoke wanted to be at rest in the sky and the stars wanted to remain in the heaven. He thought that a body is in its natural state when it is at rest and an external agent is needed to keep a body in constant motion otherwise the body will return to its natural state.
It was Newton who first proposed the laws of motions in (1687), in his well-known book the Principia.
Motion
In physics, motion is the phenomenon in which an object changes its position over time. Motion is mathematically described in terms of displacement, distance, velocity, acceleration, speed, and time. We will discuss all these terms one by one in our upcoming episodes. Basically, four types of motions are found in nature.
Types of Motion
- Linear Motion
- Circular Motion
- Rotation
- Vibration
Linear Motion
Today we will only discuss linear motion. If an object is moving from point A to Point B without taking any turn, it is known as linear motion. So, if an object goes from point A to point B, and comes back from point B to Point A, it is still a linear motion. But if an object goes from point A to Point B without taking any turn, then he takes a turn and goes to point C without taking any turn between point B to point C. In this case, motion between point A to point B and Pont B to Point C is linear motion but the motion between point A to Point C in not a linear motion. Simple enough, linear motion is anything that moves in a straight line without taking any turn between two points.
To explain this motion mathematically, we need to understand origin, distance, and displacement. We will use these terminologies in out upcoming episodes for a better understanding.
- Initial point: the starting point of any motion is known as initial point of the motion or the origin.
- Final point: the end point of any motion is known as final point.
- Distance: total length of path travelled by the object is called distance
- Displacement: the separation between initial and final point of the motion is known as Displacement.
For a better understanding, let’s take an example. Let’s suppose an object is moving from point A in a straight line 20 meters to a point B. New goes back on the same path 5 meter closer to point A and stops there. Let’s name this point C.
In this motion, point A is Initial Point. Point C is Final Point. Total distance travelled is length of path travelled by the object. Which is (distance from point A to point B + distance from point B to point C = 20+5 = 25 meter). Total displacement is the separation between initial and final point of the motion. Which is separation between point A to point C. This separation can be calculated as (Separation between point A and Point B – Separation between Point B and Point C = 20 – 5 = 15 meter)
