What is Motion in a Straight Line?

An object is said to be in motion if its position in relation to its surroundings changes over time. It is a shift in an object’s position over time. Linear motion is the only type of motion that exists. It uses only one dimension since, as its name implies, it is in a specific straight line.

Types of Linear Motion
The linear motion, also called the Rectilinear Motion can be of two types:

Uniform linear motion with constant velocity or zero acceleration
Non-Uniform linear motion with variable velocity or non-zero acceleration

The simplest type of one-dimensional motion is linear motion. According to Newton’s first law of motion, “an object will either be at rest or continue to move in a straight line with a uniform velocity unless and until an external force is applied to it.“

It is advised that you distinguish between general motion and linear motion. Linear motion is a one-dimensional motion, as we already stated. However, motion is typically defined as having both a magnitude and a direction, therefore an object’s position and velocity are expressed as vector quantity.

Uniform Motion in a Straight Line

A body is considered to have uniform motion if it moves in a straight line and covers the same distance in the same period of time. Simply put, a body is said to have uniform acceleration if the velocity change rate is constant.

Example:

If a car travels at a speed of 60 km/hour, it will cover a 1 km/minute. The acceleration of a car is uniform in this sense.

Non-uniform Motion in a Straight Line

In contrast to uniform acceleration, a body is said to be moving non-uniformly when its rate of change differs at various times throughout its motion and its velocity varies by unequal amounts across equal time intervals.

Example:

Football is being kicked by a boy. Depending on the boy’s exerted velocity, it might travel 4 metres on the first try, 6 metres on the second, 9 metres on the third, and so on.

Motion in a Straight Line Formulas
Following are the formulas of motion in a straight line:

v = u + at

s = ut + 1/2 at²

v² = u² + 2as