Solar energy is converted into electricity using photovoltaic (PV) cells or concentrating solar power plants. Photovoltaic cells convert sunlight directly into electricity. solar energy for home Individual photovoltaic (PV) cells are combined in modules of about 40 cells to form a solar panel; 10 to 20 solar panels are used to power a typical home. […]

# Energy_21

## Fishing rod as a lever

Let’s see how Fishing rod acts as a specific class of lever, and why it is used. When we use a fishing rod to cast a line, the rod works as a class 3 lever. Fulcrum and load are at 2 opposite ends of the fishing rod. Effort (force) is applied in between fulcrum and […]

## Crowbar as a lever

Crowbar – One of the simplest kinds of lever is the crowbar, which is a class 1 lever. We use a crowbar to lift very heavy objects off the ground. The fulcrum of the crowbar is in between the effort and the load. The distance between fulcrum and effort(force applied) is called the effort arm, […]

## Comparing three Classes of Levers

All three classes of levers make work easier, but they do so in different ways. In this post, we will discuss a few distinguishing pointers of three types of levers. And, these pointers will help to compare three classes of levers structurally and functionally. Compare levers belonging to three classes – In a first-class lever, […]

## Compound machines

Some of the machines you use every day are made up of several simple machines. Two or more simple machines that operate together form a compound machine. Look at the can opener in Figure 1. Compound machine – a can opener To open the can, you first squeeze the handles together. The handles act as […]

## Gear as a simple machine

A gear is a wheel and axle with the wheel having teeth around its rim. When the teeth of two gears interlock, the turning of one gear causes the other gear to turn. features of a gear When two gears of different sizes are interlocked, they rotate at different rates. Each rotation of the larger […]

## Types of pulleys and how they differ in their operation

In this post, we will discuss three types of pulleys, and how they operate, and how they differ in their operation and utilities. The types we will discuss are (1) Fixed Pulleys, (2) Movable Pulleys, (3) the Block and Tackle.

## Equations valid for elastic collisions

In this post, we will briefly mention the equations valid for elastic collisions. We can use these equations to solve numerical problems related to elastic collisions. The Equation for the conservation of momentum (for elastic collision) Now, to solve problems involving one-dimensional elastic collisions between two objects, we can use the equation for the conservation […]

## AQA GCSE Physics – Equations & Formulae from Energy chapter

The image below shows a list of equations and formulae from the chapter “Energy” of the GCSE Physics syllabus. This is also helpful for all other equivalent boards like CBSE, ISC, ICSE. Equations to learn from Energy chapter of physics syllabus

## Numerical problems based on the efficiency of machines

In this post, we will first find out what the efficiency of a machine means, and then we will solve numerical problems using the concept and formula of the efficiency of machines. If a machine, such as an electric motor, is used to raise a load, electrical energy must be provided to the motor. This […]

## Potential Energy Diagrams of different types

In this post, we will draw different types of Potential Energy Diagrams. Each of these diagrams is based on a specific equation of potential energy. For elementary courses and the College Board exams, the most important types of potential energy are gravitational potential energy and spring potential energy, also known as “harmonic oscillator potential energy.” […]

## Various forms of energy

Energy is defined as the capacity to do work. The various forms of energy can be classified as:• Mechanical (kinetic and potential)• Heat• Radiant (electromagnetic)• Chemical (potential)• Sound• Electrical/magnetic• Nuclear In the following sections, we will discuss each of the above-mentioned forms of energy. Mechanical energy Mechanical energy includes both kinetic and potential energy. Friction […]

## The total energy of an orbiting body or satellite – equation derivation with sample numerical

In this post, we will derive the equation of the total energy of an orbiting body, and then will solve a numerical problem using the formula derived. Derive the formula of the total energy of an orbiting body (or satellite) To calculate the total energy of an orbiting body (say a satellite) we have to […]

## Microwave ovens working principle & physics behind its operation

In this post, we will briefly discuss the science behind the operating principle of the microwave oven. This marvelous invention somehow heats only the soft parts of the food and leaves the inorganic and hard materials, like ceramic and the surfaces of bone, at approximately the same temperature. A neat trick, indeed, but how is […]

## Numerical problems on Specific Heat Capacity with solutions

In this post, we will solve a few interesting numerical problems based on specific heat capacity. Learn more about Specific heat capacity here. Solving numerical problems using specific heat capacity formula Question 1] A tank holding 30 kg of water is heated by a 3 kW electric immersion heater. If the specific heat capacity of […]

## Calculating the Energy stored in a deformed material

Here, we will see how the Load-extension graph of a body can help us to calculate the energy stored in a deformed material. We will take two Load-extension graphs for this. Energy stored in a deformed material that obeys Hooke’s law The first load-extension graph (figure 1a) belongs to a body that obeys Hooke’s law, […]

## Shape change by Forces & stretching a spring

Let’s discuss the application of forces to change the shape of an object and the concept of elasticity related to this shape change. We will cover the stretching of spring as a case study. If one force only is applied to an object then the object will change speed or direction. If we want to […]

## Conservation of energy in Levers

In this post, we will discuss how the conservation of energy is maintained in levers and other machines. A machine is a device used to multiply forces or simply to change the direction of forces. The concept that underlies every machine is the conservation of energy. A machine cannot put out more energy than is […]

## How is Pulley a kind of lever?

A pulley is a grooved wheel with a rope, chain, or cable running along the groove. A pulley can change the direction of the input force or increase the output force, depending on whether the pulley is fixed or movable. A system of pulleys can change the direction of the input force and make the […]

## How to solve projectile motion problems using Conservation of energy

In some situations, the use of conservation of energy can be a much simpler method to solve projectile motion problems than using the kinematics equations. Solving projectile motion problems makes use of the fact that Ek + Ep = constant at every point in the object’s flight (assuming no loss of energy due to friction). […]

## Transfers between kinetic & potential energy in a simple pendulum

In this post, we will discuss how transfers between kinetic energy and potential energy happen in a simple pendulum. We will also discuss Energy Conservation in a Simple Pendulum. Finally, we will derive the equation for the maximum speed of the pendulum bob. How Transfer between KE and PE happens in a simple pendulum? A […]

## Numerical Problems on Energy transformation or conversion with relevant theory – physics

Energy is transferred or transformed from one energy form to another via an energy pathway. In this post, we will briefly discuss the following topics: (a) different forms of energy (b) different mechanisms of energy transformation or conversion or transfer (c) Numerical problems related to energy conversion or transformation with the solution. Here let’s quickly […]

## work, energy, machine – definitions

Let’s find out some important one-liner definitions from the work-energy-machine chapter in physics. work, energy, simple machine – definitions Note: Here is the link to one useful post in this blog where you will find a good collection of solved numerical problems on energy conversion or transformation.

## How to find out the Mechanical Advantage of Pulley | MA & IMA pulley

Of all simple machines, the mechanical advantage is easiest to calculate for pulleys. To find out the mechanical advantage of a Pulley, simply count the number of ropes supporting the load. That is the IMA or Ideal Mechanical Advantage of Pulley. Once again we have to exert force over a longer distance to multiply force. To […]

## Key Equations from Work, Energy, Power & Simple Machines chapter

Here we enlist important key equations from the Work, Energy, Power & Simple Machines chapter. Equations related to Work, Power and the Work-Energy Theorem Let’s examine how doing work on an object changes the object’s energy. We will use cases related to a piece of rock to apply different equations from work & energy. Equation […]

## How to Calculate the Mechanical Advantage of a screw – formula

The screw shown in the Figure is actually a lever attached to a circular inclined plane. The lever part of these screws is a screwdriver. The distance between screw threads is called pitch and has the symbol P. L is the radius of the screw head surface. The effort is applied at the screw head surface with a turning effect using […]

## [PDF Notes] Gravity and Mechanical energy – grade 10 Notes download | class 10 physics notes on Gravity & Mechanical Energy

This Gravity and Mechanical energy Notes [PDF] is primarily for the 10th grade physics syllabus of different international boards. This also covers the class 10 physics syllabus on Gravity and Mechanical energy for boards like ICSE, CBSE, etc. This physics class note covers the theoretical as well as the numerical part of this important chapter. […]

## [pdf] Work-Energy-Power Grade 12 PDF Notes download (12th Grade physics) | class 11 physics pdf notes on work, energy, and power

This Work-Energy-Power Notes [PDF download] is primarily for the grade 12 or 12th-grade syllabus of different international boards. This also covers the class 11 physics syllabus on work, energy, and power for boards like ICSE, CBSE, etc. This physics class note covers the theoretical as well as the numerical part of this important chapter. We […]

## How to Calculate the Mechanical Advantage of a Wedge – formula

A wedge is a simple tool in the shape of a triangle. In other words, a wedge is simply two inclined planes back to back. Figure 1 shows the simple formulas for calculating the IMAs of these machines. The mechanical advantage formula for a wedge is dependent on its geometry: MA of a wedge = L / […]

## What is a machine and How Machines Make Work Easier?

A machine is any device that makes work easier by changing a force. A machine can do this by increasing the output force, or by increasing the output distance, and sometimes by changing the direction of the input force.

## Derivation of Gravitational potential energy equations

Deriving equations of Gravitational Potential Energy (1)with planet’s surface as the zero level & (2)infinity is chosen as the zero level, 1] If we choose a planet’s surface as the zero level or reference, Gravitational Potential Energy Ep at x has a positive value.

If infinity is chosen as the zero level, Ep has a negative value.

Gravitational potential energy Ep = (mg) × h = mgh (if we choose a planet’s surface as the zero level or reference).

Gravitational potential energy Ep can be expressed as Ep = – G m1m2 / r (if infinity is chosen as the zero level).

## What is the Law of Conservation of Energy and how to derive its equation? | Isolated systems – examples

The Law of conservation of energy states that the total energy of an isolated system remains constant. Now in this post, we will discuss this in detail, write its statement, and then derive an equation expressing this law of conservation of energy. So let’s begin. Law of Conservation of Energy – Explanation As per the […]

## electronvolt – what is electronvolt(eV) and how is eV related to Joule?

The SI unit of energy joule is too large a unit of energy for the microscopic world. A more convenient unit of energy for the microscopic world is the electronvolt, eV. eV by the way is not part of the SI system. What is electronvolt? | Define electronvolt We define the electronvolt as the work […]

## How to Calculate the Mechanical Advantage of Wheel and Axle?

Mechanical Advantage of Wheel and Axle = M.A = Radius of the wheel/radius of the axle = R/r. As R > r, the MA of wheel and axle is always greater than 1. Wheel and axle is actually a form of lever. The difference is that the effort arm can rotate in a complete circle […]

## Derive an expression for the potential energy of elastic stretched spring

Here we will obtain or derive an expression for the potential energy stored in the spring, also known as the elastic potential energy. To get this equation, we’ll calculate the work done to stretch or compress a spring that obeys Hooke’s law. Hooke’s law states that the magnitude of force F on the spring and the resulting deformation ΔL are proportional, F = kΔL, where k is a constant. We, therefore, derive the equation of the potential energy of a spring, also known as the elastic potential energy as follows: PE=(1/2)kx2 where k is the spring’s force constant and x is the displacement from its undeformed position.elastic potential energy represents the work done on the spring and the energy stored in it as a result of stretching or compressing it a distance x . The potential energy of the spring PEs does not depend on the path taken; it depends only on the stretch or squeeze x in the final configuration.

## Derivation of Kinetic Energy Equation in a minute | Derive Translational KE equation

The energy possessed by a moving body due to its motion is known as Kinetic Energy. Here we will derive the translational kinetic energy equation which goes like this: K = (1/2) mV2. So let’s BEGIN. How to derive the equation of Kinetic Energy? | Derive Translational KE equation Let’s take an object of mass […]

## What is the Relation between momentum and kinetic energy? | How to derive the momentum-KE equation?

The relation between momentum(p) and kinetic energy(K) of an object of mass m can be expressed with this equation: p = (2mK)(1/2) That means the square root of 2mK gives us the momentum value. Now let’s derive the equation that gives the relationship between momentum and kinetic energy. Derive an equation to show the relationship […]

## Work-Kinetic Energy Theorem with the Derivation of mathematical expression

Work-Kinetic Energy Theorem with derivation: In this post, we will discuss the special relationship between work done on an object and the resulting kinetic energy of the object and come up with the statement of the work-kinetic energy theorem. We will also see how to derive the equation of the work-kinetic energy theorem.Everyday experience supports […]

## What is Negative Work? | Friction does negative work – How?

A sign with a vector quantity denotes direction. But, Work is a scalar quantity. So a negative sign with it (i.e. a negative work) has no connection with its direction. Then what is negative work? When work done by an external force on a mass reduces the energy of that mass then we say that […]

## Difference between Ideal Mechanical Advantage (IMA) and Actual Mechanical Advantage (AMA)

Ideal Mechanical Advantage (I.M.A.) – The ratio of the total load to the effort is called Ideal Mechanical Advantage (I.M.A.) Therefore, I.M.A. =Total load/effort. [ the total load is the sum of the force to overcome the moveable parts, load due to friction, and the useful load.]Actual Mechanical Advantage (A.M.A.) – The ratio of useful […]