SATHEE: Physics

String Theory

What is String Theory?

String theory is a branch of theoretical physics that proposes that the point-like particles of particle physics are not actually points, but rather one-dimensional objects called strings. In string theory, the fundamental constituents of the universe are not particles, but rather vibrating strings. These strings can be open or closed, and they can vibrate in different ways, giving rise to different types of particles.

January 1, 0001 read

Surface Energy

Surface energy is the energy required to create a new surface area of a material. It is a measure of the intermolecular forces between the molecules at the surface of a material. The higher the surface energy, the more difficult it is to create a new surface area.

Surface energy is an important property that affects a number of applications, including adhesion, wetting, and emulsification. By understanding the factors that affect surface energy, we can better control these properties and improve the performance of materials in a variety of applications.

January 1, 0001 read

Synchrotron

A synchrotron is a type of particle accelerator that uses electromagnetic fields to propel charged particles to high speeds and energies. Synchrotrons are used in a variety of scientific research applications, including particle physics, nuclear physics, and materials science.

How Synchrotrons Work

Synchrotrons work by accelerating charged particles in a circular path. The particles are injected into the synchrotron at a low energy and then accelerated as they travel around the ring. The acceleration is achieved by using a series of magnets to create a strong magnetic field. The magnetic field causes the particles to move in a circular path and also increases their energy.

January 1, 0001 read

Tension Force

What is Tension Force?

Tension force is a pulling force that acts along the length of an object, tending to stretch or elongate it. It is not one of the four fundamental forces in physics, along with gravitational force, electromagnetic force, and strong nuclear force.

Characteristics of Tension Force

Direction: Tension force always acts in the direction opposite to the applied force.
Magnitude: The magnitude of tension force is equal to the magnitude of the applied force.
Contact force: Tension force is a contact force, which means that it can only be exerted when two objects are in contact with each other.

Examples of Tension Force

January 1, 0001 read

Terminal Velocity

Terminal velocity is the constant speed at which an object falls through a fluid (such as air or water) when the resistance of the fluid to the object’s motion is equal to the force of gravity acting on the object.

Factors Affecting Terminal Velocity

The terminal velocity of an object depends on several factors, including:

Mass: The greater the mass of an object, the greater its terminal velocity. This is because a more massive object experiences a greater force of gravity.
Cross-sectional area: The larger the cross-sectional area of an object, the greater its terminal velocity. This is because a larger cross-sectional area experiences more resistance from the fluid.
Density of the fluid: The denser the fluid, the greater the terminal velocity of an object. This is because a denser fluid exerts more resistance on the object.
Coefficient of drag: The coefficient of drag is a measure of the resistance of an object to motion through a fluid. The higher the coefficient of drag, the greater the terminal velocity of an object.

Applications of Terminal Velocity

Terminal velocity has several applications, including:

January 1, 0001 read

The International System Of Units

Seven Fundamental Units

The Seven Defining Constants are a set of fundamental physical constants that are used to describe the universe. They are:

The speed of light in a vacuum (c) = 299,792,458 meters per second
The elementary charge (e) = 1.602176634×10^-19 coulombs
The Planck constant (h) = 6.62607015×10^-34 joule-seconds
The gravitational constant (G) = 6.67430×10^-11 newton-meters²/kilogram²
The Boltzmann constant (k) = 1.380649×10^-23 joules/kelvin
The Avogadro constant (N_A) = 6.02214076×10²³ particles/mole
The molar gas constant (R) = 8.31446261815324 joules/mole-kelvin

These constants are fundamental in the sense that they are not derived from any other physical laws or theories. They are simply observed to be true, and they are used to build up all of the other laws and theories of physics.

January 1, 0001 read

Thermal Diffusivity

Thermal diffusivity is a measure of how quickly heat flows through a material. It is defined as the ratio of the thermal conductivity to the heat capacity per unit volume.

$$ \alpha = \frac{k}{\rho c_p} $$

Where:

$\alpha$ is the thermal diffusivity in m²/s
$k$ is the thermal conductivity in W/mK
$\rho$ is the density in kg/m³
$c_p$ is the specific heat capacity at constant pressure in J/kgK

Factors Affecting Thermal Diffusivity

The thermal diffusivity of a material is affected by several factors, including:

January 1, 0001 read

Thermal Energy

Thermal energy is the energy associated with the random motion of atoms and molecules in a substance. It is a form of internal energy, which is the total energy of a system excluding its kinetic and potential energy. Thermal energy is often referred to as heat, but heat is actually the transfer of thermal energy from one system to another.

Sources of Thermal Energy

Thermal energy can be generated from a variety of sources, including:

January 1, 0001 read

Thermal Expansion

Thermal Expansion of Solid

Thermal expansion is the phenomenon in which the dimensions of a solid object increase when its temperature is raised. This is due to the increased kinetic energy of the atoms or molecules in the solid, which causes them to vibrate more vigorously and move further apart from each other.

The amount of thermal expansion depends on the material of the solid and the temperature change. Some materials, such as metals, expand more than others, such as ceramics. The coefficient of thermal expansion is a measure of how much a material expands per unit temperature change.

January 1, 0001 read

Thermal Stress

Thermal stress is a type of mechanical stress that occurs due to a difference in temperature within a material or between two materials in contact. When a material is subjected to a temperature gradient, it can cause the material to expand or contract, leading to the development of internal stresses. These stresses can be significant and can cause damage to the material if they exceed the material’s strength.

January 1, 0001 read

Thermodynamic System

A thermodynamic system is a region of space that is defined for the purpose of thermodynamic analysis. The system is separated from its surroundings by a boundary, which may be real or imaginary. The boundary may be fixed or moving, and it may allow for the exchange of matter, energy, or both.

Types of Thermodynamic Systems

There are three main types of thermodynamic systems:

Open systems: These systems allow for the exchange of both matter and energy with their surroundings. An example of an open system is a room with an open window.
Closed systems: These systems allow for the exchange of energy but not matter with their surroundings. An example of a closed system is a sealed bottle of gas.
Isolated systems: These systems do not allow for the exchange of either matter or energy with their surroundings. An example of an isolated system is a thermos bottle.

Properties of Thermodynamic Systems

January 1, 0001 read

Joule’s Law

In 1840, a British scientist named James Prescott Joule found out that the heat generated in an electric circuit is directly related to the circuit’s electrical resistance. This discovery is known as Joule’s law or Joule’s heating law. Joule also suggested that heat is a type of energy, regardless of the material used in the heating process.

This article will explain Joule’s heating law, its various uses, and some examples.

January 1, 0001 read

String Theory

What is String Theory?

Surface Energy

Surface Energy

Synchrotron

Synchrotron

How Synchrotrons Work

Tension Force

What is Tension Force?

Terminal Velocity

Terminal Velocity

Factors Affecting Terminal Velocity

Applications of Terminal Velocity

The International System Of Units

Seven Fundamental Units

Thermal Diffusivity

Thermal Diffusivity

Factors Affecting Thermal Diffusivity

Thermal Energy

Thermal Energy

Sources of Thermal Energy

Thermal Expansion

Thermal Expansion of Solid

Thermal Stress

Thermal Stress

Thermodynamic System

Thermodynamic System

Joule’s Law

Medical Preparation

NCERT Books & Solutions

Important Resources

Other Resources

Syllabus

Mentorship

NCERT Exercise Video Solution

Forum

For International Students

Get In Touch

String Theory

Surface Energy

Synchrotron

How Synchrotrons Work#

Tension Force

Terminal Velocity

Factors Affecting Terminal Velocity#

Applications of Terminal Velocity#

The International System Of Units

Thermal Diffusivity

Factors Affecting Thermal Diffusivity#

Thermal Energy

Sources of Thermal Energy#

Thermal Expansion

Thermal Stress

Thermodynamic System

Joule’s Law

Medical Preparation

NCERT Books & Solutions

Important Resources

Other Resources

Syllabus

Mentorship

NCERT Exercise Video Solution

Forum

For International Students

Get In Touch

How Synchrotrons Work

Factors Affecting Terminal Velocity

Applications of Terminal Velocity

Factors Affecting Thermal Diffusivity

Sources of Thermal Energy