Answer Happy

Problem 1 (60 points) Explain your work. h nor houlder m₁ Part A (Dynamics) A barrel with building bricks (mass m₂) is initially held in place by a rope attached to a wall. Mr. Paddy Murphy (mass m₁), confident in his powers and forgetting basic physical principles, thinks he can hold the barrel and has just untied the rope (see picture). Since m₂>m₁, the assembly will begin to move. The barrel moves down through distance h, Mr. Murphy moves up through distance h, and the frictionless pulley (mass M, radius r, solid cylinder) spins (no slipping). m₁=65kg m₂=130kg M=60kg r=0.5m h=45m a. Draw (extended, if necessary) FBDs for all relevant objects. Include coord systems and labels for EACH FBD. FBD m₂ FBD M (pulley) FBD m₂ b. Use your FBDs to set up your dynamics equations. Don't solve here: m₁: F₁ m₂: F M pulley: axis of rotation c. List constraints. How are the three accelerations related? Explain any negative signs. Page 2 of 7 d. Find the acceleration for poor Mr. Murphy. e. Use your acceleration result from above and kinematics to find the speed with which Mr. Murphy's head hits the pulley at the top. m₂