Energy – Hub of related Posts

Here goes the list of our posts on Energy Physics and related topics and subtopics.

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 put into it. A machine ...
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How is Pulley a kind of lever? – physics faq

A pulley is basically a kind of lever that can be used to change the direction of a force. In some cases, a pulley or system of pulleys can multiply forces. In this post, we will see how a pulley can be described as a lever as well. simple pulley systems - with diagram Figure 1 below shows 3 types ...
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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). In other words, at each ...
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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. Often when an object moves, energy is being transferred from one type to another. For example, kinetic energy can be transferred to gravitational potential energy by doing work, and vice versa. Examples: As we throw an object upwards, kinetic energy is ...
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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 revise some fundamentals related to ...
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One-liner definitions from the work-energy-machine chapter (physics FAQ)

Let's find out some important one-liner definitions from the work-energy-machine chapter in physics. FAQ & definitions from the work-energy-simple machine chapter What is a complex machine? a machine that combines two or more simple machines define efficiency Efficiency is output work divided by input work What is energy? the ability to do work What is gravitational potential energy? energy acquired ...
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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 raise a load 1 meter ...
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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 for work[Work is the application ...
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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 ...
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[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. We hope, the students appearing ...
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[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 hope, the students appearing for ...
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How to Calculate the Mechanical Advantage of a Wedge – formula

figure 1: 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 ...
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What is a machine and How Machines Make Work Easier?

When we hear the word machine, images of power tools or construction equipment come into our minds. While these are certainly some examples of machines, devices as simple as hammers and screws are also machines. Why are simple tools like hammers and screws considered to be machines? Because like all machines, they also change forces and make work easier. What ...
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Gravitational potential energy – concepts & equations when reference varies from the planet’s surface to infinity

Gravitational potential energy, Ep, is the energy of a mass due to its position within a gravitational field. This energy can be released (and converted into kinetic energy) when the body is allowed to fall.In this post, let's find out the concepts & equations when reference varies from the planet's surface to infinity. We will discuss & derive 2 equations: ...
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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 work-energy equation the total energy ...
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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 done when a charge equal ...
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How to Calculate the Mechanical Advantage of Wheel and Axle?

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

Here we will obtain or derive an expression for the potential energy of elastic stretched spring. This energy is also known as 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 ...
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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 m which is at rest ...
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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 between momentum and kinetic energy | ...
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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 this theorem. If we see ...
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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 the work done is negative ...
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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 load to the effort is ...
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What type of lever is standing on toes? | second class lever in our body

Standing on toes acts as a second class lever (also known as class II or type 2 lever). This is an example of the presence of a lever mechanism in the human body.The foot acting as a lever arm with calf muscle supplying an upward effort, the weight of the body acting as a downward load, and the ball of ...
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What type of lever acts when we nod our head? | Nodding of Head as Lever

The nodding of the head acts as a first-class lever (also known as class I or type 1 lever). In this lever, the skull acts as the lever arm. Pivot is the place where our skull meets the top of our spine. And the neck muscles at the back of the skull provide the force (effort) to lift our head ...
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What is the use of a lever if its mechanical advantage is more than 1, equal to 1 and less than 1?

If the mechanical advantage of a lever is more than 1, a lever can act as a Force Multiplier. That means using that lever more load can be overcome by applying less amount of effort. Example, Crowbar, Bottle opener, nutcracker If the mechanical advantage of a lever is less than 1, a lever can act as a speed Multiplier. That ...
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Comparison of Scissors & shears with their mechanical advantage

Explain why scissors for cutting cloth may have blades longer than handles, but shears for cutting metals have short blades and long handles. - to explain this we need a comparison of Scissors & shears with their mechanical advantage.Scissors and shears apparently may look identical. Both of them belong to the class I lever, having the fulcrum in between load ...
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What is the Work done by Gravity on an object having Horizontal circular motion?

What is the Work done by Gravity on an object having Horizontal circular motion? Is it positive, negative, or zero work?We will set up a quick experiment for easy observation. How to set up an experiment to find out work done by gravity on a horizontally circulating object? Let’s tie a piece of stone to one end of a string ...
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Mechanical Advantage of Inclined Plane with formula

The mechanical advantage of an inclined plane is calculated as the ratio of the length of the incline and the height of the incline. It can also be calculated using the value of 1/(sin θ), where θ is the angle of inclination.An inclined plane is a simple machine that makes our life easier. All sloping, paved surfaces for walking or ...
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What Is Potential Energy?

What Is Potential Energy?Potential energy is a form of stored energy - it is the energy possessed by a body at rest due to its position or size or shape. By doing work, forces act to increase and decrease the kinetic energy of objects within a system. If the kinetic energy that’s removed can be stored and recovered later, the ...
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Forces acting on a mass sliding down an inclined plane – using vector resolution

In this post, we will discuss the forces acting on a mass sliding down an inclined plane. To do this we will take the help of the concepts of Vector Resolution. Here we are not considering the presence of friction. Forces acting on a mass sliding down an inclined plane The first step when setting up the problem is to ...
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Work Energy Power – Worksheet problem solution (Q6)

A 10 kg ball is dropped from a height of 10 m. Find (a) the initial potential energy of the ball, (b) the kinetic energy just before it reaches the ground, and (c) the speed just before it reaches the ground. (a) The initial PE = mgh = 10. 9.8 . 10 = 980 J (b) The KE just before ...
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Numerical on Work Energy Power solved worksheet class 10 ICSE, CBSE

This post is focused on Numerical Problems on Work, Energy, Power with solutions, and a problem worksheet for you. This is very useful for high school students studying Physics, more precisely for class 10 students of ICSE, CBSE, international boards like IGCSE, state boards, etc.) Numerical Problems on Work, Energy, Power | class 10 ICSE, CBSE | solved i] Find ...
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Equation of Efficiency that relates mechanical advantage and velocity ratio of an ideal machine

In this post, we will find out the equation of Efficiency that relates mechanical advantage and velocity ratio of an ideal machine. Equation of Efficiency that relates mechanical advantage and velocity ratio of an ideal machine The efficiency of a machine = Work output / Work input .... (1)Now, Work output = Load x displacement of the load ..... (2)And ...
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Numerical Problems on Lever’s mechanical advantage & velocity ratio

Here you will find Numerical Problems on Lever's mechanical advantage & velocity ratio. Try to solve and if required refer to the solutions given. We will continuously add newer problems. Numerical Problems on Lever's mechanical advantage & velocity ratio 1 ) Calculate the mechanical advantage of a class 2 lever such that the length of the rod is 2 meter ...
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What is the Velocity Ratio formula of a machine?

Velocity Ratio Formula is the topic of this physics notes. Here we will see what Velocity Ratio (V.R.) is and then quickly state its formula or equation. V.R. is a term related to a machine that gives an idea of whether there is any speed gain or force multiplication or direction change of the effort for that machine. V.R. lets ...
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What Is Power? – concepts and units and formula

Power is the rate at which work is done or the rate at which energy is supplied or used. Like work and energy, power is also a scalar quantity.The SI unit for power is Joules per second (Js-1), which is defined to be a Watt (W). So 1 W = 1 J/s. There are other popular units like Kilowatt and ...
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Types of levers

Types of levers - Levers are classified according to the relative positions of fulcrum, load, and effort points in the lever body. We will discuss different types of levers with examples in this post. So, let's start. How many types of levers are available? On the basis of the location of fulcrum, load, and effort in the lever body, levers ...
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Mechanical advantage Formula of simple machines

In this post, we will talk about the Mechanical advantage formula for different simple machines. Just to give you a quick heads up, the Mechanical Advantage of a machine is the ratio of output force and the input force. In other words, it is the ratio of Load and Effort. Now to understand these in detail we need to understand ...
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Freefall FAQs, velocity & displacement variation, Energy conservation, & Kinetic Energy during freefall

In this post, we will find out (a) how to find the weight of a freely falling body (b) How the velocity of a freely falling body changes every second if we ignore air drag force (air resistance)? (c) Why do we feel weightless during freefall (d) Kinetic energy of a body under free fall (e) Applicability of Law of ...
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Work done by a force – Equation, Case studies, and FAQs

In Physics Work is done by a force only if the object on which the force is applied makes a displacement. Without this displacement, work done is zero irrespective of the force you have applied. Work done by a force depends on the 3 parameters: (a) the force applied (b) The displacement and (c) The angle between the line of ...
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Mechanical Advantage of a Lever with Formula

MA of a lever & its formula The mechanical advantage of a lever is the ratio of the load the lever overcomes and the effort a person or system applies to the lever to overcome some load or resistance. In simple words and as per the formula, it's the ratio of load and effort. The formula of the mechanical advantage(MA) of ...
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