What is Natural-radioactivity? All the elements beyond hydrogen and helium were made in nuclear reactions in the interiors of stars or in explosive supernovas. Both radioactive and stable nuclides are created in these processes. The solar system is composed of nuclides that were formed about 4.5×109 years ago. (How this is determined is discussed later in this section). Most of ...

Read More »## kepler’s 3 laws of planetary motion definition and equation

What are kepler’s three laws of planetary motion? Using newton’s laws of motion and law of universal gravitation,we can understand and analyze the behavior of all the bodies in the solar system:the orbits of the planets and comets about the sun and of natural and artificial satellites about their planets.We make two assumption that simplify the analysis: We consider the ...

Read More »## Simple harmonic motion (S.H.M):Definition,formulas and examples

Simple harmonic motion is defined as:”When the net force is directly proportional to the displacement from the mean position and is always directed towards mean position.” A body is said to be vibrating if it moves back and forth or to and fro about a point.Another term for vibration is oscillation.A special kind of vibratory or oscillatory motion is called ...

Read More »## Inductance of a solenoid derivation

What is the solenoid? The solenoid is defined as:”A long tightly wound cylindrical conducting wire is called solenoid.” Inductance of a solenoid Now we will prove “Inductance of a solenoid derivation”. Consider a solenoid having n turns per unit length.When current passes through the solenoid, magnetic field is produced inside the solenoid which is directed along the axis of the ...

Read More »## bohr atomic model and theory for hydrogen atom with postulates

Bohr’s theory of the hydrogen atom The Rutherford model of the atom and the experimental formula of atomic spectra helped Bohr is solving the problem of atomic structure.In 1913 he proposed a model for the structure of a hydrogen atom based on his experimental observations. Bohr atomic model postulates Neil Bohr based his theory of hydrogen atom on the following ...

Read More »## sound intensity level and loudness with examples

“Sound energy passing per second through a unit area held perpendicular to the direction of propagation of sound waves is called intensity of sound.”The sound waves transfer energy from the sounding body to the listener.The intensity of sound depends on the amplitude of sound waves.Intensity is a physical quantity and can be measured accurately.The unit of intensity of sound is ...

Read More »## Moment of inertia equation and formulas of rigid objects

Moment of inertia is defined as:”The sum of the products of the mass of each particle of the body and square of its perpendicular distance from axis.” Or : The product mass and the square of the perpendicular distance from the axis of rotation is known as moment of inertia. I = mr² For a rigid body moving about ...

Read More »## Difference between density,mass and volume with examples

Mass and density are two physical quantities.Mass is the quantity of matter of an object while density is mass per unit volume.They are two different quantities but these quantities have relationships with each other, higher will be the mass higher will be the density. Now! We are going learn in detail about mass and density. What is mass? The mass of ...

Read More »## Examples of transverse and longitudinal waves

All waves can be classified into two kinds: transverse waves, and longitudinal waves.water waves, light waves, rope waves and radio waves are the examples of transverse waves, while sound waves and waves which are produced from vertical oscillating spring under tension are few examples of longitudinal waves. Now! Stay with us to know the examples of transverse and longitudinal waves ...

Read More »## Kirchhoff’s voltage and current law with examples

What is Kirchhoff’s Voltage Law? Kirchhoff’s voltage law is a fundamental circuit law that states that the algebraic sum of all the voltages around a closed path is zero or, in other words,the sum of the voltage drops equals the total source voltage. Kirchhoff’s loop rule In an electric circuit, the voltages across the resistors(voltage drops) always have polarities opposite ...

Read More »