What is Work energy theorem: Definition and 108 Discussions

In physics, work is the energy transferred to or from an object via the application of force along a displacement. In its simplest form, it is often represented as the product of force and displacement. A force is said to do positive work if (when applied) it has a component in the direction of the displacement of the point of application. A force does negative work if it has a component opposite to the direction of the displacement at the point of application of the force.
For example, when a ball is held above the ground and then dropped, the work done by the gravitational force on the ball as it falls is equal to the weight of the ball (a force) multiplied by the distance to the ground (a displacement). When the force F is constant and the angle between the force and the displacement s is θ, then the work done is given by:




W
=
F
s
cos
⁡

θ



{\displaystyle W=Fs\cos {\theta }}
Work is a scalar quantity, so it has only magnitude and no direction. Work transfers energy from one place to another, or one form to another. The SI unit of work is the joule (J), the same unit as for energy.

View More On Wikipedia.org
Recent contents Top users
  1. B

    Need Help with Work Energy Theorem Problem

    I am having some problems, I am on the work energy theorem and I had to do some problems for homework. For one of the questions I was not given enough information. I am supposed to find the initial velocity, when they tell us the final velocity is zero, the coefficient of friction is 0.42...
  2. M

    Work energy theorem force diagram

    I am working on the following problem. Susan's 13.0 kg baby brother Paul sits on a mat. Susan pulls the mat across the floor using a rope that is angled 30 degrees above the floor. The tension is a constant 31.0 N and the coefficient of friction is 0.190 . Use work and energy to find Paul's...
  3. V

    Solving the Work Energy Theorem for an Observer Moving Left

    A 2kg block at rest on a frictionless surface is pulled for 2s by a 10N horizontal force (pull to the right). Use the Work Energy Theorem to determine the final velocity from the perspective of an observer moving to the left. Does the WET still work that observer? I did the calculations...
  4. R

    Work Energy Theorem in Moving reference frames

    This is a highly theoretical question... so beware! The Work Energy(WE) equation in Mechanics says that the net total work done on an object due to various conservative and non-conservative forces equals the change in kinetic energy of the body. This above theorem is usually derived simply from...
  5. D

    Work Energy Theorem and kinetic energy

    The work energy theorem says that ''The work done by the net force acting on a body results change only in its kinetic energy. '' But if the resultant force is in vertically up direction it will surely change its potential energy too, so what's the solution here.
  6. marlon

    Newtonian Mechanics, Motion on Inclines, Work Energy Theorem

    Let's start with the very base of Newtonian mechanics. It works like this : Suppose we work in two dimensions denoted by a x-axis and an y-axis. You can work in as many dimensions as you want because all you have to do is add a unit vector to the formula's, as you will see. Starting from the...
  7. F

    Work energy theorem problems cracking my heard

    Hello members Please could you help me with solutions for the following two problems that I am stuck with. King Kong is capable of jumping to a maximum vertical height of 10 m. He picks up Enrico Fermi, who is exactly 10% of Kong's mass, and leaps upwards. To what maximum height can King...
  8. L

    Work Energy Theorem Question I cant do

    I have no clue how to do b, c and especially d. Thanks The cable of the 1,800 kg elevator cab in Fig. 8-51 snaps when the cab is at rest at the first floor, where the cab bottom is a distance d = 3.9 m above a cushioning spring whose spring constant is k = 0.14 MN/m. A safety device clamps...
Back
Top