Generalization of WE equation to cover rotation

Generalization of WE equation to cover rotation -...

Info icon This preview shows pages 1–2. Sign up to view the full content.

Generalization of WE equation to cover rotation So our WE equation remains, But now we include the fact that work can be done by torques according to the equation above, and that if an object is rotating, it has an additional KE of: Example If the disk is rotating at a rate of 3 rad/s. What F must be applied to slow it down to rest in 5 rev.? We apply the WE equation. The work done on the disk is that done by the torque supplied by F. The energy of the disk is purely rotational kinetic energy. Example: Pushing open a door Suppose you’re trying to push open a door of mass 50kg, width 1m, and height 2.5m. If the hinges exert a counter torque of τ hinge = -100N·m z . If you apply a force of 220 N, how fast will the door be rotating by the time you’ve pushed it through an angle of 30 degrees? The situation is illustrated, top-down, below: We can apply the WE equation to the door. Since the hinge force and F-force are non-conservative, and since the change in energy of the door is purely kinetic, we have, So,
Image of page 1

Info icon This preview has intentionally blurred sections. Sign up to view the full version.

Image of page 2
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

What students are saying

  • Left Quote Icon

    As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

    Student Picture

    Kiran Temple University Fox School of Business ‘17, Course Hero Intern

  • Left Quote Icon

    I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

    Student Picture

    Dana University of Pennsylvania ‘17, Course Hero Intern

  • Left Quote Icon

    The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

    Student Picture

    Jill Tulane University ‘16, Course Hero Intern