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ENGR5004 / Week 7
Dynamics L14 Worked example 2TutorialOld spec ENGR2162:212 min

ENGR216 Dynamics L14 worked example 2 (slides 15-16) official answers

A 200 kg cart has its centre of mass G 0.2 m above the ground. Its wheels A (rear, left) and B (front) touch the ground 0.3 m to the left and 0.2 m to the right of G respectively. A force P=50P = 50 N is applied to the end of the handle, which is 0.6 m to the right of G and 0.5 m above the ground; P is directed downwards and to the left at 60∘60^\circ to the horizontal, pushing the cart to the left. Neglect the mass of the wheels and rolling resistance; take g=9.81g = 9.81 m/s2^2.

Find the acceleration of the cart and the normal reactions at wheels A and B.

Cart with G 0.2 m above the ground; wheel A 0.3 m left of G, wheel B 0.2 m right of G; handle end 0.4 m beyond B and 0.5 m above the ground, where P = 50 N pushes down and to the left.
Cart with G 0.2 m above the ground; wheel A 0.3 m left of G, wheel B 0.2 m right of G; handle end 0.4 m beyond B and 0.5 m above the ground, where P = 50 N pushes down and to the left.
Formulas you may need
  • Rigid-body translation: ∑Fx=m(aG)x\sum F_x = m(a_G)_x, ∑Fy=m(aG)y\sum F_y = m(a_G)_y, ∑MG=0\sum M_G = 0 (learn this)