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## Natural Radioactivity and its applications

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 ...

What is radioactive decay? “Radioactive decay  is the process by which the nucleus of an unstable atom loses energy by emitting radiation, including alpha particles, beta particles, gamma rays and conversion electrons.” Most of the nuclides that have been identified are radioactive.That is,they spontaneously emit a particle,transforming themselves in the process into a different nuclide . In this section we discuss the two ...

## What is the difference between Ampere’s Law and Biot-Savart’s Law?

What is ampere’s law? According to this law “The line integral of magnetic field B along a closed path due to current is equal to the product of the permeability of free space and the current enclosed by the closed path”. Mathematically it is expressed as: Where μ0=permeability of free space i=current flowing through the conductor. Proof: Consider a straight ...

## How to find density with mass and volume?

What is Density? “Mass per unit volume  of a material is called density.”Density is an important property of any material.A homogeneous material such as ice or iron has the same density throughout.We use  (the Greek letter rho) for density.If a mass m of homogeneous material has volume V ,the density  is: Two objects made of the same material have the ...

## Formula for Potential energy

What is potential energy? Potential energy is defined as:“Energy due to position is called potential energy.” When a diver jumps off a high  board into a swimming pool,he hits the water moving pretty fast,with a lot of kinetic energy.Where does that energy come from?The answer is that gravitational force (his weight) does work on the diver as he falls.The diver’s ...

## kinematic Viscosity of water

What is Viscosity? “Viscosity is the  internal friction in a fluid.”Viscous forces opposes the motion of one portion of a fluid relative to another.Viscosity is the reason it takes effort to paddle a canoe through calm water,but it is also the reason the paddle works.Viscous effects are important in the flow of fluids in pipes,the flow of blood,the lubrication of ...

## Work energy theorem problems with solutions

What is the work energy theorem? Work energy theorem states that:“The net work done by the forces acting on the body is equal to the change in kinetic energy of the body.”Mathematically it is expressed as: Wnet = Kf –Ki = ∆k An unbalanced force applied to a particle will certainly change the particle’s state of motion.Newton’s second law provides us with ...

## kepler's laws of planetary motion

kepler’s 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 gravitational force only ...