Lab 10: Torque Background: All of us come into constant contact with physical interactions that lead to applying a torque on a system. Think of using your hand to turn on the knob on the door, or tightening a bolt or turning that pizza in the oven. In this lab, we will explore concepts such as torque and its application to rotational dynamics. Torque, defined as the cross product of Force and Radius is itself a vector quantity (perpendicular to both force and radius). Torque indicates an action capable of producing angular acceleration. Today, we will explore measurements of torque on a meter stick resting on a fulcrum. The goal is to achieve equilibrium such that the meter stick experiences no rotation - the summation of all torques on the system equals zero. F = Fxr =F *r *sin (0) Torque Distance Force Source: AllMyCircuits Objectives: Measure torque on an equilibrium system Free-body diagrams of multiple torque actions on a system of equilibrium . Materials: Clamps Fulcrum Meter stick Extra mass Mass hangerProcedure: SupTOT :Of dad For this experiment, we will use the following configuration of meter stick on a fulcrum to explore the effects of torque. You can use clamps to hold the meter stick to the fulcrum as well as hang extra masses during the experiment. Clamp Meter Stick Fulcrum Hanging weight Measure the mass of the meter sticks and clamps Mass stick = 0. 09 13 kg Massclamp = 0. 0 167 kg Part A: Torque of Two Masses 1. Place one of the clamps approximately at the center of the meter stick 2. Place the meter stick with the clamp on the fulcrum. 3. Adjust the clamp and the position of the meter stick until it is balanced (stable equilibrium). Record this position of the clamp as Xo on data table 1. 4. Place another clamp at X = 15cm on the meter stick and hang a mass of 200g (this is your weight 1). Also record the lever arm 1: this will be the distance that Weight 1 is acting with respect to the rotating point (distance from the fulcrum) 5. At the other end of the meter stick, place a clamp at position of 75cm. Keep adding weights to this clamp until the meter stick is balanced (horizontal). Record the position and mass for system2 6. While keeping the left side the same (System 1), remove the masses from the second clamp and add 50g. 7. Slide the mass and clamp of system 2 until you have reached equilibrium (meter stick is horizontal). Record the position of clamp 2 in your data table below 45 Cm From 8. Complete the data table by calculating torque for both systems. center point XO Lever arm 2 Torque 2 Trials Weight 1 Lever arm 1 Torque 1 Weight 2 ( m ) (N*m) (N) ( m ) (N*m) (N) 1 200 9 0-15 30 114 - 455 . 455 51 . 81 2 200 9 0 .15 30Part B: Multiple Components of Torque 1. Remove all the hanging weights from the setup. 2. On the left side, position a clamp at x=25cm with a hanging mass of 100g. 3. On the right side of the fulcrum, position a clamp at x=x0+10cm with a mass of 150g. 4. Calculate where you must place the third clamp with a weight of 30g to balance the meter stick - 392 ? -98 Calculated position of 3d clamp =_ - 4 . 1 ( . 25 ) (9. 8 5. Record the actual position of the third clamp. - 1 ( . 15 ) ( 9.8 ) Xclamp3 = 40 ) m - 1 ( 9 - 8 ) = . 98 Part C: A Balancing Act - 392 6. Remove all the masses and clamps from the setup. 7. Place a clamp at x=20cm on the meter stick and position the meter stick on the fulcrum 98 8. What do you notice about the setup? Is the meter stick balanced? Why? = . 4 9. To the left, add a clamp at x=10cm with a hanging mass of 200g. 10. Add another clamp to the right of the meter stick at x=60cm. 11. Using the previous knowledge from Parts A & B, calculate the amount of mass you must add to the clamp on the right in order for the system to be at equilibrium Calculated mass on the right clamp = 12. Add masses to the clamp on the right and record this value -4 ( 9.8 ) ( - 1 ) = - 39 Measured mass on right clamp =. 940 9 ( 1 ) ( 9- 8 ) ( x ) - 08 x =. 392Analysis: Part A: 1. From data table 1, what needed to happen to both systems so that the meter stick was at equilibrium? 2. Draw the free body diagram of the system for one of the trials. Part B: 1. How does you calculation of Step 4 (partB) matched to the real measurement of the position of the clamp? What can account for the error between what you calculated and the actual position? Part C: 1. How does your calculated mass at step 11 (part C) compared to the actual mass need to keep the system in equilibrium? 2. Redraw you free body diagram to correctly account for all the torques. 3. Using the correct body diagram, recalculate the mass in step 11 to match what you have measured