1 / 17

Moment of a Force

Moment of a Force. Learning Objectives. recall and use the relationship between the moment of a force and its distance from the pivot: Moment = force x perpendicular distance form pivot recall that the weight of a body acts through the centre gravity Define the torque of a couple.

delano
Download Presentation

Moment of a Force

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. Moment of a Force

  2. Learning Objectives recall and use the relationship between the moment of a force and its distance from the pivot: Moment = force x perpendicular distance form pivot recall that the weight of a body acts through the centre gravity Define the torque of a couple

  3. Moments Forces can make objects turn if there is a pivot.

  4. The see-saw In order to make the seesaw turn about its pivot, forces have to be applied on either side of the plank

  5. What happens when one person moves closer to the fulcrum or pivot? The turning effect of the force is also dependent on the distance of the force from the pivot. The see-saw

  6. Turning effect the turning effect is called the moment of force (or simply "moment“) the distance is called the moment arm (or lever arm) of the force.

  7. Moment of a Force • To work out a moment, we need to know two things: • the force or weight applied • the distance from the pivot that the force or weight is applied. • Force and distance must be perpendicular to each other

  8. Moment of a Force • Product of force and the perpendicular distance • From the pivot

  9. Moment and Equilibrium • Conditions for Equilibrium • Net force is zero • Net moment is zero at any point

  10. Example Find the force F that will balance the seesaw.

  11. Example Find the force F that will balance the seesaw.

  12. Center of gravity The centre of gravity of an object is the point where the whole weight of the object may be considered to act.

  13. Center of gravity For a regularly-shaped object, the centre of gravity is at its centre and, where supported there, it balances.

  14. Example • A uniform plank, 100 cm long and weighing 1.0 N is balanced at its midpoint by a support. A weight of 1.20 N is hanged 5 cm from the left end. It was found out that an unknown weight W would balance the plank if it is positioned 72 cm from the left end. • What is the weight W of the object? • How much force is exerted by the support on the plank?

  15. Couple • Two parallel forces equal in magnitude • But opposite in direction • Has a turning effect about a pivot located midway between them

  16. Torque of a Couple • Product of • One of the forces • And the distance between them

  17. Your turn! Answer numbers 1 to 4, page 56

More Related