Ch. 11 Torque Worksheet (pdf) - Coal City High School

TORQUE PROBLEMSShow all work. Circle your answer. Use g = 10m/s 2 .T = F rTorque = force (perpendicular) times lever arm (distance from force to fulcrum)1. Dave the Plumber exerts a 10.0 N force on the wrench. If he holds thewrench 15.5 cm from the pipe (fulcrum for this lever), determine thetorque he applies to the system.2. Ned tightens a bolt in his car engine by exerting 12N of force on his wrench at adistance of 0.40 m from the fulcrum. How much torque must Ned produce to turn thebolt?3. Mabel and Maude are seesawing on the school playground and decide to see if theycan move to the correct location to make the seesaw balance. Mabel weighs 400.0N andshe sits 2.00m from the fulcrum of the seesaw. Where should 450.0N Maude sit tobalance the seesaw?4. If a torque of 1350 Nm is exerted on a flywheel that has a diameter of1.00 m, determine the tangential force that must be exerted on the wheel.

TORQUE PROBLEMS5. Charlie wants to open a door that requires 225 Nm of torque to open. If he can exert aforce of 85.0 N, how far from the hinges must he exert the force?6. Sally faints from all the excitement! If she is 1.70 m tall (ie her center of gravity willbe at 0.85 m) and has a weight of 512 N, determine the torque that causes her to rotate.7. Nancy, whose mass is 60.0 kg, is working at a construction site and she sits down fora bite to eat at noon. If Nancy sits on the very end of a 3.00m-long plank pivoted in themiddle on a saw horse, how much torque must her co-worker provide on the other end ofthe plank in order to keep Nancy from falling on the ground?8. Barry carries his tray of food to his favorite cafeteria table for lunch. The 0.50m-longtray has a mass of 0.20kg and holds a 0.40kg plate of food 0.20m from the right edge.Barry holds the tray by the let edge with one hand, using his thumb as the fulcrum, andpushes up 0.10 m from the fulcrum with his finger tips. How much upward force musthis finger tips exert to keep the tray level?

TORQUE PROBLEMS9. Tracey is building a mobile to hang over her baby's crib. She hangs a 0.020kg toysailboat 0.010m from the left end and a 0.015kg toy truck 0.20m from the right end of abar 0.50m long. If the lever arm itself has negligible mass, where must the support stringbe placed so that the arm balances?10. Roger and Ann, two paramedics, rush a 60.0kg man from the scene of an accident toa waiting ambulance, caring him on a uniform 3.00kg stretcher held by the ends. Thestretcher is 2.60m long and the man's center of mass is 1.00m from Ann. How muchforce must Roger and Ann each exert to keep the man horizontal?11. A steel beam of uniform cross section weighs 2.5 X 10 5 N. If it is 5.00m long, whatforce is needed to lift one end of it?12. A painter weighing 875N stands on a uniform plank 3.00m long which is supportedat each end by a stepladder. The plank weighs 223N. If the painter stands 1.00m fromone end of the plank, what force is exerted by each stepladder?

TORQUE PROBLEMSBONUS: A bar 4.0m long weighs 400.0N. Its center of gravity is 1.5m from one end. Aweight of 300.0N is attached at the heavy end and a weight of 500.0N is attached at thelight end. What is the magnitude and the point of application of the force needed to keepthe bar horizontal?