POTENTIAL ENERGY DIAGRAM
In physics the terms of mechanical energy usually refers to Potential energy (U) and Kinetic Energy (K). In the absence of non-conservative, or dissipative forces, these energies obey the law of conservation of energy, or ΔU + ΔK = 0. That is, when a system is only acting under the influence of conservative forces its total energy content never changes, the energy just converts between forms.

At any point in the cycle, the total energy is constant, U + K = Umax = Kmax. Remember our two relationships involving work

The work done by a conservative force decreases an object's potential energy while it is increasing its kinetic energy

Defining the initial potential energy Uo = 0, gives us

Using the calculus, we see that our desired expression of the instantaneous restoring force being equal to the negative derivative of the potential energy function.
See also this Potential Energy diagram.

The curve represents the value of potential energy U as a function of the particle's coordinate x. The horizontal line above the curve represents the constant value of the total energy of the particle E. The total energy E is the sum of kinetic ( K) and potential ( U) energies of the particle. ( U <= E)

In the slope of zero, F=0, is said to be the state of equilibrium. This terms means the net force act on the object is zero and initially There are two kinds of equilibrium: * Stable equilibrium means that small deviations from the equilibrium point create a net force that accelerates the particle back toward the equilibrium point (think of a ball rolling between two hills). * Unstable equilibrium means that small deviations from the equilibrium point create a net force that accelerates the particle further away from the equilibrium point (think of a ball on top of a hill) * Neutral equilibrium occur when the force is zero for some distance. If it is displaced to one side the force is still zero

...Experiment 4: Work, Power and Energy
Maria Isabela Mendoza, Carmela Miranda, Arianne Nagrampa, and Vivien Oreo
Department of Biological Sciences
University of Santo Tomas
España, Manila, Philippines
Abstract
The experiment performed involved work, power and energy. On the first activity, the time it took for each member to go up and down the stairs was recorded. Afterwards, the work and power done were computed. The most powerful member in the group was...

...PotentialEnergy
• Definition and Mathematics of Work
• Calculating the Amount of Work Done by Forces
• PotentialEnergy
• Kinetic Energy
• Mechanical Energy
• Power
An object can store energy as the result of its position. For example, the heavy ball of a demolition machine is storing energy when it is held at an elevated position. This stored energy of...

...examples of work done=force x distance
What is work?
Work in physics is the transfer of energy; work is done on an object when an applied force moves it through a distance. The link between work and energy is work done equals energy transferred. The units for the two are also the same (joules). E.g. 500J of work = 500J of kinetic energy.
Work is calculated with the formula: work done=force x distance moved
For example, if a force...

...WORK and ENERGY
Work done by a constant force
1- The drawing shows a plane diving toward the ground and then climbing back upward. During each of these motions, the lift force acts perpendicular to the displacement , which has the same magnitude, 1.7 × 103 m, in each case. The engines of the plane exert a thrust , which points in the direction of the displacement and has the same magnitude during the dive and the climb. The weight of the plane has a magnitude of 5.9 ×...

...Contents[Show]
The energy of an object is its ability to do work. Energy is the cause and work is its effect. Therefore both work and energy have the same units, which is joule (J) in the SI system and erg in the CGS system. Energy is also a scalar quantity. Energy exists in many forms.
Examples
Mechanical energy which is either in the form of potentialenergy or kinetic...

...joules.
D) The work done by the gravitational force is zero joules.
E) The net work done by the two forces is zero joules.
3. A helicopter (m = 3250 kg) is cruising at a speed of 56.9 m/s at an altitude of 185 m. What is the total mechanical energy of the helicopter?
A) 3.91 × 107 J D) 6.91 × 107 J
B) 5.26 × 107 J E) 1.12 × 107 J
C) 2.27 × 108 J
4. The power needed to accelerate a projectile from rest to its launch speed v in a time t is 50 W. How much...

...conservation of mechanical energy
Section: 8
Name: Ahmed Atari
University ID: 201103848
Instructor: Ahmed Zainelabdin
Submission date: May 1, 2014
Objective: the purpose of this lab is to investigate the law of conservation of energy. This can be achieved by measuring both potential and kinetic energy through the experiment conducted.
Back ground:
Kinetic...

...Tutorial – Work, Energy
(Assume the acceleration due to gravity, g = 9.81 m/s2 )
1. Calculate the work done when a force of 40 N pushes an object a distance of
500 m in the same direction as the force.
2. Calculate the work done when a mass is lifted vertically by a crane to a height of 5 m, the force required to lift the mass being 98 N.
3. A spring, initially in a relaxed state, is extended by 100 mm. Determine the work done by using a work...

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