Relating conservative force and potential energy energy diagrams and equilibrium
This presentation is the property of its rightful owner.
Sponsored Links
1 / 15

-Relating Conservative Force and Potential Energy -Energy diagrams and Equilibrium PowerPoint PPT Presentation


  • 36 Views
  • Uploaded on
  • Presentation posted in: General

-Relating Conservative Force and Potential Energy -Energy diagrams and Equilibrium. AP Physics C Mrs. Coyle. A Force is “Conservative” if:. “ the work this force does on an object that moves between two points depends only on the position of these two points and not on the path.”

Download Presentation

-Relating Conservative Force and Potential Energy -Energy diagrams and Equilibrium

An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -

Presentation Transcript


Relating conservative force and potential energy energy diagrams and equilibrium

-Relating Conservative Force and Potential Energy-Energy diagrams and Equilibrium

AP Physics CMrs. Coyle


A force is conservative if

A Force is “Conservative” if:

  • “ the work this force does on an object that moves between two points depends only on the position of these two points and not on the path.”

  • “the work this force does on an object that moves through a round trip is zero.”

  • Example: gravity, force of a spring.


Consider a ball thrown up and the system is the ball and the earth

Consider a ball thrown up and the system is the ball and the earth.

  • The work done by the force of gravity Wg =-ΔU


Relating conservative force and potential energy energy diagrams and equilibrium

For a particle moving along the x-axis (one dimensional motion)while a conservative force, in the same axis, within the system acts on it:

ΔU is the change in potential energy of the system


Solving for f x

Solving for Fx:


Example find the gravitational force for a particle a distance x above the earth s surface

Example: Find the gravitational force for a particle a distance x above the earth’s surface.

  • Start with U= mgx

  • Find F


Example find the spring force for a particle attached to a spring

Example: Find the spring force for a particle attached to a spring:

  • Start with U= ½ kx2

  • Find F(x):


Types of positions of equilibrium

Types of Positions of Equilibrium

  • Stable Equilibrium: movement away from this (x=0) position results in a restoring force.

  • Unstable Equilibrium: movement away from this position results in a force directed away from x=0

  • Neutral equilibrium: movement away from x=0 does not result in either restoring nor disruptive forces.


Energy diagrams u x vs x

Energy Diagrams, U(x) vs x


Energy diagrams u x is minimum at x 0 stable equilibrium

-Energy Diagrams -U(x) is minimum at x=0 (stable equilibrium)

xmax and –xmax :

turning points


Unstable equilibrium u x is max

Unstable equilibriumU(x) is max


Neutral equilibrium u x is constant

Neutral EquilibriumU(x) is constant


Example 1 40

Example 1 (#40)

A single conservative force acting on a particle varies as F=(-Ax+Bx2 )i N, where A and B are constants and x is in meters.

a) Calculate the potential energy function taking U=0 at x=0

b) Find the change in potential energy and change in kinetic energy as the particle moves from x=2.00m to x=3.00m


Example 2 42

Example 2 (#42)

  • A potential energy function for a two dimensional force is U=3x3y - 7x

  • Find the force that acts at the point (x, y)

  • Hint find F(x) and F(y).


  • Login