Question

A uniform beam resting on two pivots has a length L = 6.00 m and mass M = 76.5 kg. The pivot under the left end exerts a normal force nt on the beam, and the second pivot located a distance l = 4.00 m from the left end exerts a normal force nz. A woman of mass m = 56.7 kg steps onto the left end of the beam and begins walking to the right as in the figure below. The goal is to find the woman's position when the beam begins to tip. (a) What is the appropriate analysis model for the beam before it begins to tip? rigid object under net force O rigid object in static equilibrium particle under net force particle in equilibrium (b) Sketch a force diagram for the beam, labeling the gravitational and normal forces acting on the beam and placing the woman a distance x to the right of the first pivot, which is the origin. Choose File No file chosen This answer has not been graded yet. (c) Where is the woman when the normal force ny is the greatest? x = (d) What is n, when the beam is about to tip? (e) Use Fext = 0 to find the value of n, when the beam is about to tip. N 7ext = 0, with torques computed around the second pivot, find the woman's position x when the beam is about to tip. (f) Using the result of part (d) and m (9) Check the answer to part (e) by computing torques around the first pivot point. m

Answer 1

equillibrity & rigid 1 object in static mg Mg 5 На р - t = 4y - L = Em © to have a greatest women is at a=om @ when seam about to tip, there is no longer conto bean so, n, ON o & Euzo nyth2-ug-Mg-o of M2- 56.7(9.8) 765(9,8) 0 12E 1305.36N ② st exto about and giver nila) - mg (4-u)- M9 (3)0 o(4) - 56769,81(4-0)- 76.5(9.8) (120 & Thirst piusto mg() + Mg(s) – n. (4) 20 9.858.7x + 76.5 (9.8) 1- D 1305.369) Go xa 5.349 m x 5342 M