Honors Physics – Static Equilibrium and Torque Worksheet 1. A uniform, 100-g meter stick is placed atop a fulcrum positioned at 65 cm. Where would a 150-g mass be hung from the meter stick such that it would be balanced? [75 cm] 2. The same meter stick as in the above problem is now placed atop a fulcrum positioned at 30 cm. The meter stick has a 20-g mass attached at 96 cm and a 100-g mass attached at 22 cm. Where would a 200g mass be positioned such that the meter stick is balanced? [17.4 cm] 6. A window washer is standing on a scaffold supported by a vertical rope at each end. The scaffold weighs 200 N and is 3.00 m long. What is the tension in each rope when the 700-N worker stands 1.00 m from one end? [567 N, 333 N] 7. 3. A beam resting on two pivots has a length of L = 6.00 m and a mass M = 90.0 kg. One pivot is to the far left while the other is a distance l = 4.00 m from the left edge of the beam. A woman of mass m = 55.0 kg starts walking along the beam as shown. At what distance x from the left edge of the beam will the woman be just as the beam starts to tip? [5.63 m] In the arrangement of tackle boxes and fish in equilibrium, what is the mass of the fish? Assume the bar is massless. [3.0 kg] 4. 8. A 50-N bowling ball is held in a person’s hand horizontally as shown above. Find the upward force exerted by the biceps on the ulna, and downward force exerted by the humerus on the ulna. [583 N, 533 N] 5. A 50-N, 10-m long uniform ladder rests on the side of a smooth vertical wall, and is held in place by friction with the floor below. If the ladder just starts to slip at a 50° angle with the floor, what is the coefficient of friction between the ladder and the floor? [0.420] Hey Yogi! A hungry 700-N bear walks out on a 6-m long, 200-N beam to get an 80-N pic-anic basket as shown. Note that the beam is connected to the wall by a hinge. (a) If the wire can support a maximum of 900 N, at what distance x would the wire break? (b) What is the tension T in the wire, and what are the vertical and horizontal forces Hx and Hy exerted by the hinge, when the bear is at x = 1.00 m? [5.14 m, T = 343 N, Hx = 172 N, Hy = 683 N]