1 / 9

PHYS 218 sec. 517-520

PHYS 218 sec. 517-520. Review Chap. 11 Equilibrium and Elasticity. What you have to know. Conditions for equilibrium for a rigid-body How to solve rigid-body equilibrium problems Only Sections 11.1 – 11.3 are reviewed. (We skipped the other sections in the class.).

ludlow
Download Presentation

PHYS 218 sec. 517-520

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. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. PHYS 218sec. 517-520 Review Chap. 11 Equilibrium and Elasticity

  2. What you have to know • Conditions for equilibrium for a rigid-body • How to solve rigid-body equilibrium problems • Only Sections 11.1 – 11.3 are reviewed. (We skipped the other sections in the class.)

  3. Conditions for equilibrium First condition for equilibrium Second condition for equilibrium If the body is at rest, it is in static equilibrium.

  4. Center of Gravity In most equilibrium problems, gravity is one of the forces that make the body rotate. We can assume that the entire force of gravity is concentrated at the center of gravity (CG) of the body. If the change in the gravitational acceleration g can be ignored, the center of gravity (CG) of the body is identical to its center of mass (CM).

  5. Center of Gravity The total gravitational torque is the same as though the total weight were acting on the CM of the body. A body supported at several points must have its CG somewhere within the area bounded by the supports. CG CG stable Not in equilibrium (non-vanishing net torque)

  6. Ex 11.1 Range of CG for equilibrium

  7. Ex 11.2

  8. Ex 11.3 CG of the ladder

  9. Ex 11.4 The negative sign means that Ey is downward. If you don’t know the direction of a force a priori, then choose an arbitrary direction. After calculation, if you get a negative value, then it means that the direction of the force is opposite to your guess.

More Related