1 / 7

ME 245 Engineering Mechanics and Theory of Machines

ME 245 Engineering Mechanics and Theory of Machines. Portion 5 Friction Fundamental. Partha Kumar Das Lecturer Department of Mechanical Engineering, BUET http : //teacher.buet.ac.bd/parthakdas/. Friction: Static and Kinetic Friction. No Friction. Friction due to driving force P.

acrow
Download Presentation

ME 245 Engineering Mechanics and Theory of Machines

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. ME 245 Engineering Mechanics and Theory of Machines Portion 5 Friction Fundamental Partha Kumar Das Lecturer Department of Mechanical Engineering, BUET http://teacher.buet.ac.bd/parthakdas/

  2. Friction: Static and Kinetic Friction No Friction Friction due to driving force P Fm is maximum static force impending the motion Laws of Friction: Fm = μs N Fk = μk N NOTE: Friction force F increases with increase in driving force P and reaches to a maximum value Fm. Fkdepends upon ONLY normal force and can not increase or decrease with change in driving force P.

  3. Problem 5.1 (Beer Johnston_10th edition_P8.1 and P8.2) Determine whether the block shown is in equilibrium and find the magnitude and direction of the friction force whenθ= 25° and P = 750 N P = 150 N

  4. Problem 5.2 (Beer Johnston_10th edition_P8.13) The coefficients of friction are μs= 0.40 and μk=0.30 between all surfaces of contact. Determine the smallest force P required to start the 30-kg block moving if cable AB is attached as shown Cable AB is removed. ANS. (a)P = 353 N ← (b)P = 196.2 N ←

  5. End of Portion 5

  6. References • Vector Mechanics for Engineers: Statics and Dynamics • Ferdinand Beer, Jr., E. Russell Johnston, David Mazurek, Phillip Cornwell.

More Related