PHYS 115, Mechanics: Problem Set 7 1) Consider an Aframe with a crosspiece of negligible weight and two 4m long sides of 300 kg, all connected by frictionless pivots. Given that the crosspiecc is approximately massless, you can treat like a rope under tension T. Calculate T assuming the sides are resting on a frictionless oor. 2) A 3.7m long beam of 800 kg is connected to a frictionless pivot at one end with the other end resting on a frictionless incline. A 300 kg Iliass hangs from the beam 3m from the pivot. Determine the magnitudes of the forces from the incline and the pivot on the beam. Hint: start by calculating the normal force from the incline using torques. 3) A crane of mass I'LL lifts a spherical object of mass 1115. The boom of the crane has a mass of 1145 and a length Lb. Assume the centre of mass crane is midway between the wheels which are separated by a distance Lw. Calculate horizontal position of the centre of mass of the combined system relative to wheel at the end of the boom as a function of the angle of the boom. 9. Determine the maximum angle 9m\" that boom can be lowered Without the crane tipping, assuming LC 2 2.5 m, Lb = 8m. 11-1,; 2 10, 000 kg1 ill-{b = 500 kg: and WIS : 2.000 kg