# What is work-energy theorem prove it class 11?

The work energy theorem states that work done on a body is equal to the net change in its energy. (P.E or K.E) Proof: Consider a body of mass ‘m’ moving with an initial velocity u. Let a constant force F acting on a body changes its velocity to v.

## What is the work-energy theorem?

The work-energy theorem states that the net work done by the forces on an object equals the change in its kinetic energy.

## What is the formula of work-energy theorem?

W net = K B − K A . According to this theorem, when an object slows down, its final kinetic energy is less than its initial kinetic energy, the change in its kinetic energy is negative, and so is the net work done on it. If an object speeds up, the net work done on it is positive.

## What is the work-energy theorem Why is it important?

The work-energy theorem states that the total work done by all of the forces on the object is equal to the change in kinetic energy of the object. This theorem is important because it allows us to predict the direction, speed, or energy of a moving object.

## What is the work-energy theorem quizlet?

The work-energy theorem states that work done on a system by an external force is equal to the sum of the changes in the kinetic and potential energies of the system.

## What two concepts are related by the work-energy theorem?

Which best summarizes a concept related to the work-energy theorem? When work is positive, the environment does work on an object. When work is negative, the environment does work on an object. When work is positive, the kinetic energy in a systemremains constant.

## Who gave work-energy theorem?

W = Δ K E = 1 2 m v 2 2 − 1 2 m v 1 2 . The subscripts 2 and 1 indicate the final and initial velocity, respectively. This theorem was proposed and successfully tested by James Joule, shown in Figure 9.2.

## Where can we apply work-energy theorem?

The application of the Work-Energy theorem is that it is very useful in analyzing situations where a rigid body should move under several forces. A rigid body cannot store the potential energy in its lattice due to its rigid structure and it can only possess kinetic energy.

## How do you calculate work-energy and power?

1. work done = force × distance moved in direction of force.
2. change in gravitational energy = mgh.
3. power = work donetime taken, power = rate of energy transfer.
4. power = force × velocity.
5. efficiency = useful energy transferredtotal work done × 100 %

## How do you find the energy formula?

The equation developed by Albert Einstein, which is usually given as E = mc2, showing that, when the energy of a body changes by an amount E (no matter what form the energy takes), the mass (m) of the body will change by an amount equal to E/c2.

## How does work-energy theorem apply in real life?

Definition of the Work-Energy Theorem In words, this means that when an object slows down, “negative work” has been done on that object. An example is a skydiver’s parachute, which (fortunately!) causes the skydiver to lose KE by slowing her down greatly.

## What is work-energy theorem prove it for constant?

According to the work-energy theorem, the net work on an object causes a change in the kinetic energy of the object. The formula for net work is net work = change in kinetic energy = final kinetic energy – initial kinetic energy.

## What is work-energy simple definition?

Work is the transfer of mechanical energy from one object to another. Since work is a movement of energy, it is measured in the same units as energy: joules (J).

## What is work and energy short definition?

Work is defined as transferring energy into an object so that there is some displacement. Energy is defined as the ability to do work. Work done is always the same. Energy can be of different types such as kinetic and potential energy.

## What is work and energy short answer?

Work: It is defined as the product of force applied and the distance moved by the body on the application of the force. In SI it is measured in joule. Energy : It is defined as the capacity of a body to do work.

## What are the 2 formulas for work?

What are the Versions of the Work Formula? Mathematically, the concept of work done W equals the force f times the distance (d), that is W = f. d and if the force is exerted at an angle θ to the displacement, then work done is calculated as W = f . d cos θ.

## Why cos theta is used in work?

The horizontal component is found by multiplying the force F by the cosine of the angle between F and d. In this sense, the cosine theta in the work equation relates to the cause factor – it selects the portion of the force that actually causes a displacement.

## What is the simple formula for work?

To express this concept mathematically, the work W is equal to the force f times the distance d, or W = fd. If the force is being exerted at an angle θ to the displacement, the work done is W = fd cos θ.

## What is the difference between work-energy and power?

Work is referred to as the displacement of an object when a force (push or pull) is applied to it while energy is referred to as the capacity to do the work. It exists in various forms like potential, kinetic, chemical, thermal, nuclear, electrical energy and so on. Power is the work done per unit of time.

## Is work-energy theorem only for conservative forces?

Work-energy principle is valid regardless of any non conservative force. A s long as we are using the work done by the resultant force the work energy theorem is valid. Hence work-energy theorem is valid in the presence ofall types of forces i.e External force, Internal force and Conservative force.

## What is the SI unit of work?

The SI unit of workunit of workThe SI unit of energy is same as that of work, which is joule (J).https://byjus.com › the-si-unit-of-energy-is-newtonjoulepascal-1The SI unit of energy is. – Byju’s is the joule (J). It is defined as the work done by a force of one newton through a distance of one metre.

## What are the limitations of work-energy theorem?

what are the limitation work energy theorem ? (2) does not define spontaneity of process, like say there is an body on the floor, assume it’s Potential energy to be zero(PEi) if we say that without any external force it attains height h and specific kinetic energy which sums(KEf+PEf) to be zero(PEi).

## Is work-energy theorem valid for all forces?

The work-energy theorem can be applied in the cases of conservative forces, non-conservative forces, internal forces, external forces, and so on. Thus, the work-energy theorem is valid for all types of forces.

## What is work-energy theorem is not valid for?

Since the dynamics of a body cannot be explained in a non-inertial framenon-inertial frameA non-inertial reference frame is a frame of reference that undergoes acceleration with respect to an inertial frame. An accelerometer at rest in a non-inertial frame will, in general, detect a non-zero acceleration.https://en.wikipedia.org › wiki › Non-inertial_reference_frameNon-inertial reference frame – Wikipedia with real forces only so work-energy theorem is not valid but if we consider pseudo forces and Newton’s laws can be applied and non-inertial frame can be treated as an inertial frame and work-energy theorem is valid.