Relating conservative force and potential energy energy diagrams and equilibrium
Download
1 / 15

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


  • 54 Views
  • Uploaded on

-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.”

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about ' -Relating Conservative Force and Potential Energy -Energy diagrams and Equilibrium' - todd-rosa


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


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 F motion)while a conservative force, in the same axis, within the system acts on it:x:


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 spring:

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

xmax and –xmax :

turning points


Unstable equilibrium u x is max
Unstable equilibrium spring:U(x) is max


Neutral equilibrium u x is constant
Neutral Equilibrium spring:U(x) is constant


Example 1 40
Example 1 (#40) spring:

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) spring:

  • 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).


ad