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ENGR5004 / Week 7
ENGR216 2021 Dynamics Q A3Past paperOld spec ENGR2162:116 marks19 min

ENGR216 Summer 2021 Dynamics Q A3[VALID]

Figure A3 shows a slider mechanism that connects a wheel crank to the slider block B via link arm AB. If slider block B has a velocity vB=1v_B = 1 m/s to the right, and acceleration aB=2 m/s2a_B = 2\ \mathrm{m/s^2}, positive to the right as shown in the figure, determine:

Figure A3: wheel of radius 0.1 m connected by link AB (0.5 m) to slider block B moving right.
Figure A3: wheel of radius 0.1 m connected by link AB (0.5 m) to slider block B moving right.
Formulas you may need
  • Relative velocity: vB=vA+ω×rB/A\mathbf v_B = \mathbf v_A + \boldsymbol\omega \times \mathbf r_{B/A} (learn this)
  • Relative acceleration: aB=aA+α×rB/A−ω2rB/A\mathbf a_B = \mathbf a_A + \boldsymbol\alpha \times \mathbf r_{B/A} - \omega^2 \mathbf r_{B/A} (learn this)
  • Rolling without slipping: vO=ωrv_O = \omega r, aO=αra_O = \alpha r; contact point has zero velocity (learn this)
  • Instantaneous centre of zero velocity (IC) method (learn this)
  1. (a)
    The angular velocity of link arm AB
    [3]2:2
  2. (b)
    The angular acceleration of link arm AB
    [5]
  3. (c)
    The angular acceleration of the wheel
    [5]
  4. (d)
    State any assumptions that you have made, with full justification
    [3]Third