Uniformly Accelerated Motion - Constant Acceleration, Uniform Acceleration
The difference between uniform motion and non-uniform motion is an important concept in physics. In uniform motion, an object covers equal distances in equal intervals of time, which means its speed remains constant throughout the motion. On the other hand, in non-uniform motion, an object covers unequal distances in equal intervals of time or its direction changes, so its speed is not constant. Uniform motion has zero acceleration, while non-uniform motion involves acceleration. Most objects in real life move with non-uniform motion, such as vehicles in traffic or a falling object. Understanding this difference helps students solve problems easily and build a strong foundation in motion concepts for exams and practical applications.
Uniformly Accelerated Motion
Uniformly accelerated motion is a type of motion in which an object’s acceleration remains constant throughout the motion. In simple terms, it means the velocity of the object changes by equal amounts in equal intervals of time. This kind of motion is very common in real life, such as a car increasing its speed steadily or an object falling under gravity.
When acceleration is constant, the motion follows a predictable pattern. Since acceleration is the rate of change of velocity, constant acceleration means the velocity is changing at a uniform (constant) rate.
Example of uniform acceleration
There can be various examples of uniformly accelerated motion are :
1. Motion of a ball dropped from a height a body moving with a constant speed in a straight line has a uniform motion.
2. Motion of a bicycle going down the slope of a road when the rider is not paddling and the wind resistance is negligible .
3. A freely falling body is also an example of uniformly accelerated motion.
4. Motion of earth around the sun and many more.
Also read -
Uniform Acceleration Equations
In uniformly accelerated motion, the acceleration of an object remains constant. To describe such motion, we use a set of equations called the equations of motion. These equations help us calculate important quantities like initial velocity, final velocity, displacement, time, and acceleration.
$
\begin{aligned}
& v=u+a t \\
& s=u t+\frac{1}{2} a t^2 \\
& v^2=u^2+2 a s
\end{aligned}
$
where,
$\mathrm{v}=$ final velocity of the particle
$\mathrm{u}=$ initial velocity of the particle
$\mathrm{s}=$ displacement of the particle
a = acceleration of the particle
$t=$ time interval in which the particle is in consideration
Uniformly Accelerated Motion in a Plane
Uniformly accelerated motion in a plane refers to the motion of an object in two dimensions (2D) where the acceleration remains constant. Unlike motion in a straight line, here the object moves along both xaxis and y-axis simultaneously.
In this type of motion, acceleration can be resolved into two components:
- $\mathrm{a}_{\mathrm{x}}$ (acceleration along x -axis)
- $\mathrm{a}_{\mathrm{y}}$ (acceleration along y -axis)
Both components act independently, and we can apply the equations of motion separately in each direction.
Equations of Motion in 2D
Along $x$-axis:
- $v_x=u_x+a_x t$
- $x=u_x t+\frac{1}{2} a_x t^2$
Along y-axis:
- $v_y=u_y+a_y t$
- $y=u_y t+\frac{1}{2} a_y t^2$
Difference Between Uniform and Non-Uniform Motion
Uniform motion and non-uniform motion are two basic types of motion in physics. The main difference lies in how the speed or velocity changes with time.
Uniform Motion
Uniform motion is the motion in which an object covers equal distances in equal intervals of time, no matter how small the time interval is.
Non-Uniform Motion
Non-uniform motion is the motion in which an object covers unequal distances in equal intervals of time or its direction changes.
| Uniform Motion | Non-Uniform Motion |
| Covers equal distances in equal time | Covers unequal distances in equal time |
| Speed remains constant | Speed changes with time |
| Acceleration is zero | Acceleration is not zero |
| Graph is a straight line | Graph is a curved line |
| Simple to analyze | More complex motion |
Also Read:
- NCERT solutions for Class 11 Physics Chapter 3 Motion in a straight line
- NCERT Exemplar Class 11 Physics Solutions Chapter 3 Motion in a straight line
- NCERT notes Class 11 Physics Chapter 3 Motion in a straight line
Also check-
- NCERT Exemplar Class 11th Physics Solutions
- NCERT Exemplar Class 12th Physics Solutions
- NCERT Exemplar Solutions for All Subjects
NCERT Physics Notes:
Frequently Asked Questions (FAQs)
If velocity of a particle increases with time then its acceleration is said to be positive acceleration whereas if the velocity of a particle keeps on decreasing it is known as negative acceleration or deceleration.
If we take a particle moving in xy coordinate plane with a constant acceleration a located at point b at time t which has a position coordinate r and velocity v. It reaches point b’ has a position coordinate r’ and velocity v’ . Constant acceleration a is equal to change in velocity by time.
Freefall is the downward motion under the influence of gravity in other words when the only force acting on an object is gravity the object is said to be in freefall in vacuum that is in no air all objects in freefall accelerate at the same rate regardless of mass likewise a ball falling down with negligible air resistance. Freefall objects falling unaffected by air resistance owners we can’t fall without air resistance but for normal situation the numbers are realistic when things fall they constantly accelerate if we can ignore air resistance all objects excellent at the same rate that is at the acceleration due to gravity on earth at sea level.
In constant acceleration the body moving in a particular direction does not change its direction whereas in uniform acceleration the particle covers an equal distance in equal duration of time hence in both the situation acceleration of the body is zero.
Uniform motion meant uniform velocity but uniform speed is change in direction likewise for uniform circular motion hair the speed of the particle remains same but the direction of particle keeps on changing.
