Topics
Physical World
Physical World and Measurement
Units and Measurements
 International System of Units
 Measurement of Length
 Measurement of Mass
 Measurement of Time
 Accuracy, Precision and Least Count of Measuring Instruments
 Errors in Measurements
 Significant Figures
 Dimensions of Physical Quantities
 Dimensional Formulae and Dimensional Equations
 Dimensional Analysis and Its Applications
 Need for Measurement
 Units of Measurement
 Fundamental and Derived Units
 Length, Mass and Time Measurements
 Introduction of Units and Measurements
Kinematics
Motion in a Plane
 Scalars and Vectors
 Multiplication of Vectors by a Real Number or Scalar
 Addition and Subtraction of Vectors  Graphical Method
 Resolution of Vectors
 Vector Addition – Analytical Method
 Motion in a Plane
 Motion in a Plane with Constant Acceleration
 Projectile Motion
 Uniform Circular Motion (UCM)
 General Vectors and Their Notations
 Motion in a Plane  Average Velocity and Instantaneous Velocity
 Rectangular Components
 Scalar (Dot) and Vector (Cross) Product of Vectors
 Relative Velocity in Two Dimensions
 Cases of Uniform Velocity
 Cases of Uniform Acceleration Projectile Motion
 Motion in a Plane  Average Acceleration and Instantaneous Acceleration
 Angular Velocity
 Introduction of Motion in One Dimension
Motion in a Straight Line
 Position, Path Length and Displacement
 Average Velocity and Average Speed
 Instantaneous Velocity and Speed
 Kinematic Equations for Uniformly Accelerated Motion
 Acceleration (Average and Instantaneous)
 Relative Velocity
 Elementary Concept of Differentiation and Integration for Describing Motion
 Uniform and Nonuniform Motion
 Uniformly Accelerated Motion
 Positiontime, Velocitytime and Accelerationtime Graphs
 Position  Time Graph
 Relations for Uniformly Accelerated Motion (Graphical Treatment)
 Introduction of Motion in One Dimension
Laws of Motion
 Aristotle’s Fallacy
 The Law of Inertia
 Newton's First Law of Motion
 Newton’s Second Law of Motion
 Newton's Third Law of Motion
 Conservation of Momentum
 Equilibrium of a Particle
 Common Forces in Mechanics
 Circular Motion and Its Characteristics
 Solving Problems in Mechanics
 Static and Kinetic Friction
 Laws of Friction
 Inertia
 Intuitive Concept of Force
 Dynamics of Uniform Circular Motion  Centripetal Force
 Examples of Circular Motion (Vehicle on a Level Circular Road, Vehicle on a Banked Road)
 Lubrication  (Laws of Motion)
 Law of Conservation of Linear Momentum and Its Applications
 Rolling Friction
 Introduction of Motion in One Dimension
Work, Energy and Power
 Introduction of Work, Energy and Power
 Notions of Work and Kinetic Energy: the WorkEnergy Theorem
 Kinetic Energy
 Work Done by a Constant Force and a Variable Force
 Concept of Work
 The Concept of Potential Energy
 Conservation of Mechanical Energy
 Potential Energy of a Spring
 Various Forms of Energy : the Law of Conservation of Energy
 Power
 Collisions
 Non  Conservative Forces  Motion in a Vertical Circle
Motion of System of Particles and Rigid Body
System of Particles and Rotational Motion
 Motion  Rigid Body
 Centre of Mass
 Motion of Centre of Mass
 Linear Momentum of a System of Particles
 Vector Product of Two Vectors
 Angular Velocity and Its Relation with Linear Velocity
 Torque and Angular Momentum
 Equilibrium of Rigid Body
 Moment of Inertia
 Theorems of Perpendicular and Parallel Axes
 Kinematics of Rotational Motion About a Fixed Axis
 Dynamics of Rotational Motion About a Fixed Axis
 Angular Momentum in Case of Rotation About a Fixed Axis
 Rolling Motion
 Momentum Conservation and Centre of Mass Motion
 Centre of Mass of a Rigid Body
 Centre of Mass of a Uniform Rod
 Rigid Body Rotation
 Equations of Rotational Motion
 Comparison of Linear and Rotational Motions
 Values of Moments of Inertia for Simple Geometrical Objects (No Derivation)
Gravitation
 Kepler’s Laws
 Newton’s Universal Law of Gravitation
 The Gravitational Constant
 Acceleration Due to Gravity of the Earth
 Acceleration Due to Gravity Below and Above the Earth's Surface
 Acceleration Due to Gravity and Its Variation with Altitude and Depth
 Gravitational Potential Energy
 Escape Speed
 Earth Satellites
 Energy of an Orbiting Satellite
 Geostationary and Polar Satellites
 Weightlessness
 Escape Velocity
 Orbital Velocity of a Satellite
Properties of Bulk Matter
Mechanical Properties of Fluids
 Thrust and Pressure
 Pascal’s Law
 Variation of Pressure with Depth
 Atmospheric Pressure and Gauge Pressure
 Hydraulic Machines
 Streamline and Turbulent Flow
 Applications of Bernoulli’s Equation
 Viscous Force or Viscosity
 Reynold's Number
 Surface Tension
 Effect of Gravity on Fluid Pressure
 Terminal Velocity
 Critical Velocity
 Excess of Pressure Across a Curved Surface
 Introduction of Mechanical Properties of Fluids
 Archimedes' Principle
 Stoke's Law
 Equation of Continuity
 Torricelli's Law
Thermal Properties of Matter
 Heat and Temperature
 Measurement of Temperature
 Idealgas Equation and Absolute Temperature
 Thermal Expansion
 Specific Heat Capacity
 Calorimetry
 Change of State  Latent Heat Capacity
 Conduction
 Convection
 Radiation
 Newton’s Law of Cooling
 Qualitative Ideas of Black Body Radiation
 Wien's Displacement Law
 Stefan's Law
 Anomalous Expansion of Water
 Liquids and Gases
 Thermal Expansion of Solids
 Green House Effect
Mechanical Properties of Solids
Thermodynamics
 Thermal Equilibrium
 Zeroth Law of Thermodynamics
 Heat, Internal Energy and Work
 First Law of Thermodynamics
 Specific Heat Capacity
 Thermodynamic State Variables and Equation of State
 Thermodynamic Process
 Heat Engine
 Refrigerators and Heat Pumps
 Second Law of Thermodynamics
 Reversible and Irreversible Processes
 Carnot Engine
 Isothermal Processes
 Adiabatic Processes
Behaviour of Perfect Gases and Kinetic Theory of Gases
Kinetic Theory
 Molecular Nature of Matter
 Gases and Its Characteristics
 Equation of State of a Perfect Gas
 Work Done in Compressing a Gas
 Introduction of Kinetic Theory of an Ideal Gas
 Interpretation of Temperature in Kinetic Theory
 Law of Equipartition of Energy
 Specific Heat Capacities  Gases
 Mean Free Path
 Kinetic Theory of Gases  Concept of Pressure
 Assumptions of Kinetic Theory of Gases
 RMS Speed of Gas Molecules
 Degrees of Freedom
 Avogadro's Number
Oscillations and Waves
Oscillations
 Periodic and Oscillatory Motion
 Simple Harmonic Motion (S.H.M.)
 Simple Harmonic Motion and Uniform Circular Motion
 Velocity and Acceleration in Simple Harmonic Motion
 Force Law for Simple Harmonic Motion
 Energy in Simple Harmonic Motion
 Some Systems Executing Simple Harmonic Motion
 Damped Simple Harmonic Motion
 Forced Oscillations and Resonance
 Displacement as a Function of Time
 Periodic Functions
 Oscillations  Frequency
Waves
description
 Projectile
 Projectile Motion
 Equation of path of a projectile
 Oblique projectile
 Time of flight
 Maximum height of a projectile
 Horizontal range
 Horizontal projectile
 Trajectory of horizontal projectiie
 Instantaneous velocity of horizontal projectile
 Direction of instantaneous velocity
 Time of flight
 Horizontal range
notes
Projectile Motion
What is Projectile?
Projectile is any object thrown into the space upon which the only acting force is the gravity. In other words, the primary force acting on a projectile is gravity. This doesn’t necessarily mean that the other forces do not act on it, just that their effect is minimal compared to gravity. The path followed by a projectile is known as trajectory. A baseball batted or thrown and the instant the bullet exits the barrel of a gun are all examples of projectile.
What is Projectile Motion?
When a particle is thrown obliquely near the earth’s surface, it moves along a curved path under constant acceleration that is directed towards the centre of the earth (we assume that the particle remains close to the surface of the earth). The path of such a particle is called a projectile and the motion is called projectile motion. Air resistance to the motion of the body is to be assumed absent in projectile motion.
In a Projectile Motion, there are two simultaneous independent rectilinear motions:
1. Along xaxis: uniform velocity, responsible for the horizontal (forward) motion of the particle.
2. Along yaxis: uniform acceleration, responsible for the vertical (downwards) motion of the particle.
Accelerations in the horizontal projectile motion and vertical projectile motion of a particle:
When a particle is projected in the air with some speed, the only force acting on it during its time in the air is the acceleration due to gravity (g). This acceleration acts vertically downward. There is no acceleration in the horizontal direction which means that the velocity of the particle in the horizontal direction remains constant.
Parabolic Motion of Projectiles:
Let us consider a ball projected at an angle θ with respect to horizontal xaxis with the initial velocity u as shown below:
If any object is thrown with the velocity u, making an angle Θ from horizontal, then the horizontal component of initial velocity = u cos Θ and the vertical component of initial velocity = u sin Θ. The horizontal component of velocity (u cos Θ) remains the same during the whole journey as herein, no acceleration is acting horizontally.
The vertical component of velocity (u sin Θ) gradually decrease and at the highest point of the path becomes 0. The velocity of the body at the highest point is u cos Θ in the horizontal direction. However, the angle between the velocity and acceleration is 90 degree.
The point O is called the point of projection; θ is the angle of projection and OB = Horizontal Range or Simply Range. The total time taken by the particle from reaching O to B is called the time of flight.
For finding different parameters related to projectile motion, we can make use of different equations of motions:
Total Time of Flight:
Resultant displacement (s) = 0 in Vertical direction. Therefore, by using the equation of motions:
gt^{2} = 2(u_{y}t – s_{y}) [Here, u_{y} = u sin θ and s_{y} = 0]
i.e. gt^{2} = 2t × u sin θ
Therefore, the total time of flight (t):
Horizontal Range:
Horizontal Range (OA) = Horizontal component of velocity (u_{x}) × Total Flight Time (t)
R = u cos θ × 2 u sinθ × g
Therefore in a projectile motion the Horizontal Range is given by (R):
Maximum Height:
It is the highest point of the trajectory (point A). When the ball is at point A, the vertical component of the velocity will be zero. i.e. 0 = (u sin θ)^{2} – 2g H_{max} [s = H_{max}, v = 0 and u = u sin θ]
Therefore in a projectile motion the Maximum Height is given by (H_{max}):
The equation of Trajectory:
Let, the position of the ball at any instant (t) be M (x, y). Now, from Equations of Motion:
x = t × u cos θ  (1)
y = u sin θ × t –`1/2`×t^{2}g  (2)
On substituting Equation (1) in Equation (2):
This is the Equation of Trajectory in a projectile motion, and it proves that the projectile motion is always parabolic in nature.
A Few Projectile Motion Examples :
We know that projectile motion is a type of twodimensional motion or motion in a plane. It is assumed that the only force acting on a projectile (the object experiencing projectile motion) is the force due to gravity. But how can we define projectile motion in the real world? How are the concepts of projectile motion applicable to daily life? Let us see some reallife examples of projectile motion in two dimensions.
All of us know about basketball. To score a basket, the player jumps a little and throws the ball in the basket. The motion of the ball is in the form of a projectile. Hence it is referred to as projectile motion. What advantage does jumping give to their chances of scoring a basket? Now apart from basketballs, if we throw a cricket ball, a stone in a river, a javelin throw, an angry bird, a football or a bullet, all these motions have one thing in common. They all show a projectile motion. And that is, the moment they are released, there is only one force acting on them the gravity. It pulls them downwards, thus giving all of them an equal impartial acceleration of.
It implies that if something is being thrown in the air, it can easily be predicted how long the projectile will be in the air and at what distance from the initial point it will hit the ground. If the air resistance is neglected, there would be no acceleration in the horizontal direction. This implies that as long as a body is thrown near the surface, the motion of the body can be considered as a twodimensional motion, with acceleration only in one direction. But how can it be concluded that a body thrown in air follows a twodimensional path? To understand this, let us assume a ball that is rolling as shown below:
Now, if the ball is rolled along the path shown, what can we say about the dimension of motion? The most common answer would be that it has an xcomponent and a ycomponent, it is moving on a plane, so it must be an example of motion in two dimensions. But it is not correct, as it can be noticed that there exists a line which can completely define the motion of the basketball. Thus, it is an example of motion in one dimension. Therefore, the choice of axis does not alter the nature of the motion itself.
Now, if the ball is thrown at some angle as shown, the velocity of the ball has an xcomponent and component and also a zcomponent. So, does it mean that it is a threedimensional motion? It can be seen here that a line cannot define such a motion, but a plane can. Therefore, for a body thrown at any angle, there exists a plane that entirely contains the motion of that body. Thus, it can be concluded that as long as a body is near the surface of the Earth and the air resistance can be neglected, then irrespective of the angle of projection, it will be a twodimensional motion, no matter how the axes are chosen. If the axes here are rotated in such a way that, then and can completely define the motion of the ball as shown below:
Thus, it can be concluded that the minimum number of coordinates required to completely define the motion of a body determines the dimension of its motion.
Few Examples of Two – Dimensional Projectiles

Throwing a ball or a cannonball

The motion of a billiard ball on the billiard table.

A motion of a shell fired from a gun.

A motion of a boat in a river.

The motion of the earth around the sun.