1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Homework Help: Mechanical Principles Dynamics of Rotating Systems

  1. May 31, 2017 #1
    1. For the mechanism shown in FIGURE 1 determine for the angle
    θ = 45°:

    (i) the velocity of the piston relative to the fixed point O (VBO)
    (ii) the angular velocity of AB about point A (i.e. ωAB)
    (iii) the acceleration of point B relative to A (aBA).

    (b) Determine the value of the angle θ (measured from vertical) when:
    (i) the velocity of point B = 0
    (ii) the angular velocity of link AB a maximum.

    (c) What is the maximum angular velocity of link AB?

    2. Relevant equations
    Vao = Loa x ωoa

    3. The attempt at a solution
    Vao = Loa x ωoa = 0.005 x 10pi 0.1570

    velocity triangle cosθ = Vbo/Vao

    VBo =cos45 x Nao = 0.707 x 1.5708 = 1.1107 m/s^-1

    I just have no idea where to start or what numbers to use where

    Attached Files:

  2. jcsd
  3. May 31, 2017 #2
    Try to define de displacement of point B as a function of de alngle theta. You can define vectors from origin O to help you.
  4. May 31, 2017 #3


    User Avatar
    Science Advisor
    Homework Helper
    Gold Member

    That would certainly work, but is unnecessarily complicated for the specific questions asked.
    @mally baringon, if you resolve the instantaneous velocities of A and B into components along the rod and normal to the rod, what relationship must exist between them?
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted