 # Physics Formulas for Class 11

Physics is the branch of science which deals with the study of the world around us and their properties like energy in matter.

Physics of 11th standard contains top level concepts with questions and numerical problems which requires deep understanding in order to score good marks. These important formulas of physics class 11 will not only help the students in their academic exams, but also help in preparation of various competitive exams like engineering and medical entrances.

The Physics class 11 formula sheet pdf can be considered as the best tool for the preparation of physics examination for Class 11th, and also for various competitive examinations like IIT, NEET, JEE and so forth.

List of Physics Formulas Class 11 IIT

The list of physics formulas for class 11 IIT studies is given here below:

1. Work, Energy and Power

Work, energy and power are the three most used terms in Physics. They are probably the first thing that a student learns in Physics. Work and energy are considered as the two sides of the same coin.

a. Work

Definition: In physics work is said to be done whenever a force applied on an object, makes the object move.

Formula: Work is calculated by the product of applied force and the displacement of the object.

W = F × d

Unit: The SI unit of work the joule (J), also 1J = 1 Nm (newton-metre)

b. Energy

Definition: Energy is defined as the capacity of a body to do work.

Formula: The formula potential energy is given by:

P.E. = mgh

The formula for kinetic energy is given by:

K.E. = ½(mv²)

Unit: The SI unit of energy is the same as that of work, and it is joule (J), this unit is named in honour of an English physicist Sir James Prescott Joule.

c. Power

Definition: Power can be defined as the rate at which work is done i.e. energy converted.

Formula: The formula for power is

P = W/t

Unit: The unit of power is Watt (W).

2. Surface Tension Formula

Surface tension is the natural tendency of a liquid surface to resist any force applied on it. Due to surface tension, liquids tend to shrink into the minimum surface area possible. The surface of a liquid behaves like an elastic sheet.

Mathematically, surface tension is expressed as:

T=F/L

Where,

F = force per unit length

L = length in which the applied force acts

T = surface tension of the liquid

3. Simple Harmonic Motion Formula

The simple harmonic motion is a periodic motion in which the restoring force on the object is directly proportional to the displacement of the object from the mean position. The restoring force of the simple harmonic motion is always directed towards the mean position.

The acceleration of a particle under simple harmonic motion (SHM) is given by,

a(t) = -ω2 x(t).

Where,

a = acceleration of the particle

ω = angular velocity of the particle.

4. Projectile Motion Formula

The projectile motion is a motion in which a body is projected in air, following a curved path under the influence of gravity. When a body is projected in horizontal direction with a constant velocity, it undergoes free fall motion.

The formula for projectile motion is given by:

Horizontal distance: x = Vx t

Horizontal velocity: Vx = Vxo

Vertical distance: y = Vyot - ½(gt²)

Vertical velocity: Vy = Vyo  - gt

Where,

V= the velocity (along the x-axis)

Vy = the velocity (along the y-axis)

Vxo = Initial velocity (along the x-axis)

Vyo = Initial velocity (along the y-axis)

g = acceleration due to gravity

t = the time taken

The equations of the projectile motion are:

Time of flight: t =

Maximum height reached: H =

Horizontal length: R =

Where,

Vo = Initial velocity of the particle

sin θ = Component of velocity along the y-axis

cos θ = component of velocity along the x-axis

5. Gravitational Force Formula

Every object in the universe attracts every other object with a force which is directly proportional to the masses of the two objects and inversely proportional to the square of the distance between them.

Mathematically, the gravitational force formula is given by:

F = Gm1m2/r2

Where,

G = universal gravitational constant

m1 = mass of the first object

m2 = mass of the second object

r = distance between the two objects

6. Waves Motion Formulas

General equation of wave: d2y/dx2 = 1/v2 . d2y/dt2

Notation: Amplitude A, Frequency v, Wavelength λ, Period T, Angular Frequency ω, Wave Number k,

T = 1/v = 2/ ω,

U = v λ

K= 2/ λ

Progressive wave travelling with speed u:

y = f(t – x/v), => +x,

y = f(t + x/v), => -x

Progressive sine wave:

y = Asin(kx – ωt),

= Asin(2(x/ λ – t/T))

7. Sound Wave Formula

Displacement wave: s = s0sinω(t – x/u)

Pressure wave: p = p0cosω(t – x/u)

P0 = (Bω/u) s0

Speed of sound waves:

uliquid =

usolid =

ugas =

Intensity: I = 22B/u . s02v2 = p02v/2B = p02/2pv

1. Johnson is Standing on the Top of the Building, and John is Standing Down. If Johnson Tosses a Ball with Velocity 30 m/s and at the Angle of 700 then at the Time 3s What Height will the Ball Reach?

Ans-

Given:

Vyo = 30 m/s

Δ t = 3s

The Vertical velocity in y-direction is expressed as

Vy = Vyo sin 70o

Vy = 30 sin 70

Vy = 23.22 m/s

2. Gravitational Force Problems

Q i) Evaluate the Gravitational Force if the Mass of the Sun is 1.99 × 1030 kg & Earth is 5.97 × 1024 kg. They are Separated by the Distance of 1.5 × 1011 m? Here, Gravitational Constant G = 6.673 × 10-11 Nm2/Kg2.

Ans-

The gravitational force is given by:

F = Gm1m2/r2

= 6.673 * 10-11Nm/Kg2 * 1.99 * 1030kg * 5.97 * 1024lkg

F= (7.93×1044)/(2.25 × 1022)

F= 3.5 * 1022N

Q ii) What will be the Force of Gravity in Between Two Balls of Mass 2kg and 3kg Separated by 2m Distance?

Ans-

The gravitational force is given by:

F = Gm1m2/r2

= 6.673 * 10-11Nm/Kg2 * 2kg * 3kg)/2m2)

F = 1 * 10-10 N

Physics is a subject which is filled with high level concepts and complex formulas. Students should thoroughly understand the concept behind the formulas to get command over the subject. All formulas of physics class 11 as mentioned above are in a proper manner to help the students develop the concept step by step.