What is Free Body Diagram?
Free Body Diagram A diagram showing all external forces acting on an object is called "Free Body Diagram" F.B.D. In a specific problem, first, we are required to choose a body and then we find the number of forces acting on it, and all the forces are drawn on the body, considering it as a point mass. The resulting diagram is known as the free body diagram (FBD). For example, if two bodies of masses $m$ and $M$ are in contact and a force $F$ on $M$ is applied from the left fig. (a), the free body...
Read More →What is Equilibrium of Forces?
Equilibrium of Forces Forces that have zero linear resultant and zero turning effect will not cause any change in the motion of the object to which they are applied. Such forces (and the object) are said to be in equilibrium. Mathematically a body is said to be in equilibrium if (a) Net force acting on it is zero, i.e., $\vec{F}_{\text {net }}=0$ (b) Net moments of all the forces acting on it about any axis is zero. Physically the body at rest is said to be in equilibrium if it is permanently at...
Read More →What are types of Forces?
Types of Forces (a) Field Forces or Range Forces : These are the forces in which contact between two objects is not necessary. Ex. (i) Gravitational force between two bodies. (ii) Electrostatic force between two charges. (iii) Weight of a body. (b) Contact Forces : When a force involves direct contact between two bodies. One body exerts a force on another because of the contact between them. These forces originate with the atoms of each body - each atom exerts a force on its neighbor (which may ...
Read More →What are the some applications of General Equation?
Some applications of General Equation (A) Projection from a height at an angle $\theta$ above horizontal : $u_{x}=u \cos \theta \quad \quad u_{y}=-u \sin \theta$ $x=(u \cos \theta) t \quad a_{y}=+g$ $h=(-u \sin \theta) t+\frac{1}{2} g t^{2}$ $g t^{2}-(2 u \sin \theta) t-2 h=0$ $\mathrm{t}=\frac{+2 \mathrm{u} \sin \theta \pm \sqrt{(2 \mathrm{u} \sin \theta)^{2}+8 \mathrm{hg}}}{2 \mathrm{~g}}$ or $\quad t=\frac{u \sin \theta}{g} \pm \sqrt{\left(\frac{u \sin \theta}{g}\right)^{2}+\frac{2 h}{g}}$ (B...
Read More →What is Horizontal Projectile Motion?
Horizontal Projectile Motion Suppose a body is thrown horizontally from point $\mathrm{O}$, with velocity $\mathrm{u}$. Height of $\mathrm{O}$ from ground $=\mathrm{H}$. Let $X$-axis be along horizontal and $Y$-axis be vertically downwards and origin $O$ is at point of projection as shown in fig. Let the particle be at $P$ at a time $t$. The coordinates of $P$ are $(x, y)$. Distance traveled along X-axis at time t with uniform velocity i.e. velocity of projection and without acceleration. i.e. v...
Read More →What are the special Points of Oblique Projectile Motion?
Special Points of Oblique Projectile Motion : (1) The three basic equations of motion, i.e. $v=u+a t$ $s=u t+\frac{1}{2} a t^{2}$ $v^{2}=u^{2}+2 a s$ For projectile motion give : $\mathrm{T}=\frac{2 \mathrm{u} \sin \theta}{\mathrm{g}}$ $R=\frac{u^{2} \sin 2 \theta}{g}$ $H=\frac{u^{2} \sin ^{2} \theta}{2 g}$ (2) In the case of projectile motion, The horizontal component of velocity $(u \cos \theta)$, acceleration $(g)$ and mechanical energy remains constant. Speed, velocity, the vertical componen...
Read More →What is Oblique Projectile Motion?
Oblique Projectile Motion Consider the motion of a bullet that is fired from a gun so that its initial velocity $\vec{u}$ makes an angle $\theta$ with the horizontal direction. Let us take $X$-axis along the ground and $Y$-axis along vertical. $\vec{u}$ can be resolved as $\mathrm{u}_{\mathrm{x}}=\mathrm{u} \cos \theta \quad$ (along horizontal) $\ u_{y}=u \sin \theta$ (along vertical) The motion of bullet can be resolved into horizontal and vertical motion. (i) In horizontal direction there is n...
Read More →What is the principle of Physical Independence of Motions?
Principle of Physical Independence of Motions Motion of projectile is two-dimensional motion in a vertical plane. It can be resolved in two motions along horizontal vertical direction These two motions are independent of each other. This is called the principle of physical independence of motions. At any instant velocity of projectile has two components : (i) Horizontal Component : No acc. along horizontal $\left(\mathrm{a}_{\mathrm{x}}=0\right)$ so velocity along horizontal remains unchanged th...
Read More →What is Projectile Motion?
Projectile Motion A body which is in flight through the atmosphere but is not propelled by any fuel is called a projectile. A body or particle moving in the atmosphere under the effect of gravity only. The motion of the projectile is a two-dimensional motion in a vertical plane. Ex. Stone thrown in the air by a boy, Bullet fired from a gun, Javelin thrown by an athlete, Football kicked by a player, Bomb released from an airplane in flight. Trajectory: Path followed by a projectile is known as th...
Read More →What is Displacement ?
Displacement Displacement is defined as the change in the position of an object. It is a vector quantity and has a direction and magnitude. It is represented as an arrow that points from the starting position to the final position. For example- If an object moves from P position to Q, then the object’s position changes. This change in the position of an object is known as Displacement. Let the position of point $P$ at time $t_{1}$ be described by position vector $\vec{r}_{1}=x_{1} \hat{i}+y_{1} ...
Read More →What is Motion in Two Dimensions ?
Motion in Two Dimensions An object moving in a plane is said to have two-dimensional motion. The two-dimensional motion is equal to the vector sum of two one-dimensional motions along the mutually perpendicular direction. Let the position of point $P$ at a time $t$ be given by position vector $\overrightarrow{\mathrm{OP}}=\overrightarrow{\mathrm{r}}$ $\vec{r}=\hat{i} r \cos \theta+\hat{j} r \sin \theta=\hat{i} x+\hat{j} y$ Also Read JEE Physics Notes To watch Free Learning Videos on JEE by Kota’...
Read More →How to derive the Formula by Dimensional Analysis method?
Derive the Formula by Dimensional Analysis method Let a physical quantity $x$ depends on the other quantity $P, Q$ and $R$. Then $x \propto(\mathrm{P})^{\mathrm{a}}(\mathrm{Q})^{\mathrm{b}}(\mathrm{R})^{\mathrm{c}}$ $x=\mathrm{k}(\mathrm{P})^{a}(\mathrm{Q})^{b}(\mathrm{R})^{c}$ Now consider dimensional formula of each quantity in both side - $a x_{1}+b x_{2}+c x_{3}=x$ ...(2) $a y_{1}+b y_{2}+c y_{3}=y$ ...(3) $a z_{1}+b z_{2}+c z_{3}=z$ ...(4) After solving equation $(2),(3)$ and $(4)$ value of...
Read More →How to check the Accuracy of a formula ?
To check the accuracy of a formula It is based on the homogeneity principle of dimension according to it formula is correct when L.H.S. $=$ R.H.S. Dimensionally. Ex. Test the correctness of the formula $\mathrm{T}=2 \pi \sqrt{\frac{\ell}{\mathrm{g}}}$, where, $\mathrm{T}=$ time period $\ell=$ length of pendulum and $\mathrm{g}=$ Acc. due to gravity. Sol. L.H.S. Dimension Equation of $\mathrm{T} \Rightarrow \mathrm{M}^{0} \mathrm{~L}^{0} \mathrm{~T}^{1}$ R.H.S. Dimension equation of; $2 \pi \sqrt...
Read More →What are the Defects of Dimensional Analysis ?
Defects of Dimensional Analysis (i) While deriving a formula the proportionality constant cannot be found. (ii) The formula for a physical quantity depending on more than three other physical quantities cannot be derived. It can be checked only. (iii) The equations of the type $v=u \pm$ at cannot be derived. They can be checked only. (iv) The equations containing trigonometrical functions ( $\sin \theta, \cos \theta$, etc), logarithmic functions ( $\log x, \log x^{3}$ etc) and exponential functi...
Read More →What are the uses of Dimensional Equations? and what is Conversion of one system of units into another?
Uses of Dimensional Equations Following are the uses of dimensional equations. 1. Conversion of one system of units into another 2. Checking the accuracy of various formulas or equation 3. Derivation of Formula. Conversion of one system of units into another Let the numerical values are $n_{1}$ and $n_{2}$ of a given quantity $Q$ in two-unit system and the units are- $U_{1}=M_{1}^{a} L_{1}^{b} T_{1}^{c}$ and $U_{2}=M_{2}^{a} L_{2}^{b} T_{2}^{c}$ Therefore, By the principle $\mathrm{nu}=$ constan...
Read More →What is the principle of Homogeneity of Dimensions ?
Principle of Homogeneity of Dimensions The dimension of physical quantity on the left-hand side of the dimensional equation should equal to the net dimensions of all physical quantities on the right-hand side of it. Ex. If in the form $x=3 y z^{2}, x$ and $z$ represent electrical capacitances and magnetic induction the calculate the dimensional equation of $\mathrm{y}$. Sol. By the principle of homogeneity of dimension Dimension equation of $x \quad=$ Dimension equation of $\left(3 y z^{2}\right...
Read More →How to obtain dimensional formula of different Quantities ?
Dimensional formula of different Quantities Procedure : (i) Firstly we write the formula. (ii) Now change derived units in the fundamental units. (iii) At last solve the equation except for the given quantity. Note: Dimensionless quantity may have the unit. But unitless quantities are dimensionless. Ex. angle - dimensionless but it has unit radian. Also Read JEE Physics Notes To watch Free Learning Videos on JEE by Kota’s top IITian Faculties Install the eSaral App...
Read More →What is Dimensional Equation?
Dimensional Equation When a dimensional formula is equated to its physical quantity then the equation is called Dimensional Equation. Ex. Dimensional equation of Force : By $F=$ ma $\quad \Rightarrow \quad$ Dimension Equation of $F=\left[M^{1}\right]\left[L^{1} T^{-2}\right]=\left[M L T^{-2}\right]$ Ex. Dimensional equation of Energy : By $E=W=$ Force $\times$ Displacement Dimensional equation of ' $E$ ' $=\left[M^{1} L^{1} T^{-2}\right]\left[L^{1}\right]=\left[M^{1} L^{2} T^{-2}\right]$ Importa...
Read More →What are Dimensions of Physical Quantities ?
Dimensions of Physical Quantities The limit of a derived quantity in terms of necessary basic units is called dimensional formula and the raised powers on the basic units are dimensions. The basic units are represented as : Note : 1. A physical quantity may have a number of units but their dimensions would be same, Ex. The units of velocity are: $\mathrm{cms}^{-1}, \mathrm{~ms}^{-1}, \mathrm{~km} \mathrm{~s}^{-1}$. But the dimensional formula is $\mathrm{M}^{0} \mathrm{~L}^{1} \mathrm{~T}^{1}$. ...
Read More →What is Classification of Unit System?
Classification of Unit System We have the following systems of the units: CGS system: This is the centimeter-gram-second system for the units of length, mass, and time respectively. FPS system: This is the foot-pound-second system for the units of length, mass and time respectively. MKS system: The MKS system of units is a physical system of measurement that uses the metre, kilogram, and second as base units. SI System: Also known as Systeme International d'Unites. This is a complete set of unit...
Read More →What are Derived Units ?
Derived Units The units of measurement derived from the seven base units specified by the International System of Units are known as SI derived units. They are either dimensionless or can be expressed as a product of one or more of the base units, possibly scaled by an appropriate power of exponentiation. The names of SI derived units, when written in full, are always in lowercase. However, the symbols for units named after persons are written with an uppercase initial letter. For example, the s...
Read More →What are Fundamental Units?
Fundamental Units The units defined for the fundamental quantities are called fundamental units. * Triple Point of Water is the temperature at which ice, water and water vapours co-exist. Also Read JEE Physics Notes To watch Free Learning Videos on JEE by Kota’s top IITian Faculties Install the eSaral App...
Read More →Units of Measurement in Physics: Types, Properties & Examples for JEE/NEET
Home Physics Notes Units of Measurement in Physics 🚀 Checkout eSaral Courses What Is a Unit of Measurement? Every measurement in physics requires two things: a number and a unit. Saying "the car travels 60" means nothing "the car travels 60 km/h" means everything. Units give numbers their physical meaning. For students preparing for JEE Main, JEE Advanced, or NEET, a solid understanding of units and measurement is non-negotiable. NTA (National Testing Agency) consistently tests this topic in the...
Read More →What are physical quantities? and What are the Types of physical quantities?
Home Physics Notes Class 11 Physical Quantities What are Physical Quantities Those quantities that can describe the laws of physics and are possible to measure are called physical quantities. A physical quantity is that which can be measured.Note: (1) Some physical quantities are not completely specified even by magnitude, unit, and Direction. These physical quantities are called tensors. eg, moment of Inertia. (2) Physical quantity = Numerical value $\mathrm{x}$ unit 🚀 Checkout eSaral Courses T...
Read More →Atomic Structure Handwritten Notes JEE PDF - Free PDF Download
eSaral JEE JEE Main Atomic Structure Handwritten Notes JEE PDF - Free PDF Download 🚀 Checkout eSaral Courses What Is Atomic Structure and Why Does It Matter for JEE? Atomic Structure is one of the most foundational chapters in Class 11 Chemistry, and its importance in JEE cannot be overstated. According to NTA's official JEE Main syllabus, Atomic Structure falls under Physical Chemistry a section that contributes approximately 3540% of Chemistry questions in JEE Main every year. Understanding at...
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