Motion refers to the change in an object's position over a certain period of time. When an object moves from one place to another, it is said to be in motion. This change in position can be observed by comparing the object's location at different points in time. For example, if you see a car moving along the road, you can tell that it's in motion because its position changes as time goes by.
An object is considered to be at rest when it remains in the same position relative to its surroundings over a specific duration. In other words, if an object isn't changing its location with respect to the things around it, it is said to be at rest. For instance, a book sitting on a table without moving is at rest since its position isn't altering in relation to the table.
Distance refers to the total length of the path covered by an object during its entire journey from its initial position to its final position. It's a scalar quantity, which means it only has magnitude (size) and no direction. Imagine a winding road that curves and loops. The distance covered by a car along this road is the sum of all the individual segments it travels.
Displacement is the shortest straightline distance between the object's initial position and its final position. It's a vector quantity, which means it has both magnitude and direction. In the case of the car on the winding road, the displacement would be the straightline distance from where it started to where it ended up.
Distance 
Displacement 

Nature 
Distance is a scalar quantity. It only indicates how far an object has travelled. 
Displacement is a vector quantity. It provides information about both the magnitude (how far) and the direction of the change in position. 
Measurement 
Distance is the sum of all the lengths along the path travelled. 
Displacement is the shortest straightline distance between the initial and final positions. 
Values 
Distance cannot be negative or zero; it's always positive. 
Displacement can be positive, negative, or zero. 
Examples:
Uniform motion refers to the type of motion in which an object covers equal distances in equal intervals of time. In other words, the speed of the object remains constant throughout its journey. Some key characteristics of uniform motion are:
Nonuniform motion, on the other hand, occurs when an object covers unequal distances in equal intervals of time or when its speed changes at different points during its journey. Some characteristics of nonuniform motion are:
Speed is a fundamental concept in physics that measures how fast an object is moving. It quantifies the rate at which an object covers a certain distance in a given amount of time. In simpler terms, speed tells us how quickly an object changes its position relative to a reference point. Speed is a scalar quantity, which means it has magnitude (numerical value) but no direction. It only tells you how fast something is moving, not the direction in which it's moving.
Calculation of Speed
The speed of an object is calculated by dividing the distance it travels by the time it takes to cover that distance. Mathematically, the formula for calculating speed is:
Where:
Speed (v): The rate of change of distance with respect to time.
Distance (s): The length of the path covered by the object during its motion.
Time (t): The duration for which the object is in motion.
SI Unit of Speed
The International System of Units (SI) unit of speed is metres per second (ms^{1}). This unit indicates the distance covered in metres during each second of motion. It's important to use consistent units for both distance and time to obtain the correct SI unit for speed.
For example, if the distance is measured in metres and the time in seconds, then the speed will be in metres per second (ms^{1}).
Velocity is defined as the rate of change of displacement with respect to time.
While speed tells us how fast an object is moving, velocity goes a step further by incorporating the direction of motion. In other words, velocity not only tells us the rate of change of position but also specifies the direction in which the object is moving.
Calculation of Velocity
The velocity of an object is calculated by dividing the displacement it undergoes by the time it takes to undergo that displacement. Mathematically, the formula for calculating velocity is:
Where:
Velocity: The rate of change of displacement with respect to time, including direction.
Displacement: The change in position of the object, considering both magnitude and direction.
Time: The duration for which the object experiences the displacement.
SI Unit of Velocity
The International System of Units (SI) unit of velocity is metres per second (ms^{1}), just like the unit of speed. However, velocity is a vector quantity, which means it has both magnitude and direction. The unit "metres per second" specifies the distance covered in metres during each second of motion, along with the direction of motion.
Learn more about Sources of Energy 
Calculation of Average Speed
The formula for calculating average speed is:
Where:
Average Speed: The overall rate of motion of an object over a given time interval.
Total Distance Travelled: The sum of all the distances covered by the object during its motion.
Total Time Taken: The total duration of the object's motion.
Calculating Average Velocity for Uniform Motion
The formula for average velocity is:
Where:
v_{av} is the average velocity
u is the initial velocity
v is the final velocity
Calculating Average Velocity for NonUniform Motion
For nonuniform motion, where the velocity (speed and direction) of an object is changing, we can calculate the average velocity by dividing the total displacement by the total time taken. The formula for average velocity is:
It's important to note that in nonuniform motion, the total distance travelled and the total displacement can be different, leading to a distinction between average speed and average velocity.
Units of Velocity
Both speed and velocity are measured in the same units, which are commonly expressed as metres per second (ms^{1}) or, equivalently, kilometres per hour (kmh^{1}).
Acceleration is the rate at which an object's velocity changes over time. It indicates how quickly an object's speed or direction of motion changes. If an object is accelerating, it means that its velocity is changing, either by speeding up, slowing down, or changing direction.
Formula for Acceleration
The formula for calculating acceleration is:
Where:
Acceleration (a): Rate at which velocity changes with time.
Final Velocity (v): The velocity of the object at the end of the time interval
Initial Velocity (u): The velocity of the object at the beginning of the time interval
Time Taken (t): The duration over which the velocity changes
SI Unit of Acceleration
The SI unit of acceleration is metres per second squared (ms^{2}). This unit indicates that acceleration is measured in terms of how many metres per second the velocity changes over each second.
Acceleration is a vector quantity, which means it has both magnitude and direction. The direction of acceleration is determined by whether the velocity is increasing or decreasing and in which direction this change is occurring.
Uniformly accelerated motion refers to the motion of an object when its velocity changes at a constant rate (uniform acceleration). In such cases, there are a set of equations that relate various quantities, such as initial velocity, final velocity, acceleration, time, and displacement. These equations are derived from the definitions of acceleration and velocity, and they help us predict the motion of objects undergoing constant acceleration. Here are the three fundamental equations of uniformly accelerated motion:
This equation relates displacement (s), initial velocity (u), final velocity (v), acceleration (a), and time (t):
This equation relates the final velocity (v), initial velocity (u), acceleration (a), and time (t) of an object. It expresses how an object's velocity changes over time due to constant acceleration.
This equation connects the displacement (s), initial velocity (u), acceleration (a), and time (t) of an object. It allows us to calculate the distance covered by an object under uniform acceleration during a specific time interval.
This equation relates displacement (s), initial velocity (u), final velocity (v), and acceleration (a). It eliminates the time variable and provides a relationship between an object's initial and final velocities and the distance it travels.
It's important to note that these equations apply specifically to situations where the acceleration is constant and the motion is along a straight line.
A displacementtime graph, also known as a positiontime graph, depicts how an object's displacement changes over a specific period. The xaxis represents time, and the yaxis represents displacement. The slope of the graph at any point represents the object's instantaneous velocity at that moment.
A velocitytime graph illustrates how an object's velocity changes over time. The xaxis represents time, and the yaxis represents velocity. The slope of the graph at any point represents the object's acceleration at that moment.
An accelerationtime graph shows how an object's acceleration changes over time. The xaxis represents time, and the yaxis represents acceleration.
These graphs help in understanding the motion of objects in different scenarios. By analysing the slopes and shapes of these graphs, we can gather information about an object's motion, whether it's moving uniformly, accelerating, decelerating, or undergoing more complex changes.
Uniform circular motion is a specific type of motion where an object travels in a circular path with a constant speed. This type of motion has several interesting characteristics that distinguish it from other forms of motion:
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