ENGINEERING FACULTYDEPARTMENT OF MECHANICAL ENGINEERING Laboratory Report 5 The Principle of the Moment of a Force 57376514 Subject: MEM101S Technician M M Fasi Date: 29 October 2015 DANY MATANGWA Signed: I (We) swear that this is the original work of the author(s). All information obtained directly or indirectly from other sources has been fully acknowledged. TABLE OF CONTENTS 1. Aim of the Experiment 2. Theoretical Background 3. Experimental Apparatus 4. Experimental Procedure 5. Results 6. Discussion of Results 7. Conclusion Appendix A: Experimental Readings and Calculations Figure 1: Principle of the moment of a force equipment Table1: Results Table 1. AIM OF THE LABORATORY EXPERIMENT To investigate the conditions required for the equilibrium of a pivoting beam. 2. THEORETICAL BACKGROUND 3. EXPERIMENTAL APPARATUS Metre rule with a hole drilled in the middle, various mass-pieces, string, a stand with a rotation pivot. Figure 1: Principle of the moment of a force equipment 4. EXPERIMENTAL PROCEDURE Set up the apparatus as in Fig. 1, with two mass-pieces hanging on one side of the rotation point and three on the other side. Play around with the positions of the mass-pieces until the metre rule is in equilibrium. Record the masses W1, W2, W3, W4, etc and their corresponding distances from the fulcrum x1, x2, x3, x4, etc. Note which mass pieces cause clockwise rotation and which cause anticlockwise rotation. Find the sum of the clockwise moments about the fulcrum. Find the sum of the anticlockwise moments about the fulcrum. 5. RESULTS Record your readings in a table1 below. Ensure the correct use of significant figures. Table1: Results table Anticlockwise Moments Clockwise Moments Weight of Distance from Moment (N.m) Weight of Distance from Moment (N.m) mass-piece (N) Fulcrum (mm) mass-piece (N) Fulcrum (mm) W1: 0,4905 N x1: 0,175 m W1x1: 0,0858375 N.m W4: 0,4905 N x4: 0,095 m W4x4: 0,0465975 N.m W2: 0,34335 N x2: 0,105 m W2x2: 0,03605175 N.m W5: 0,4905 N x5: 0,192 m W5x5: 0,094176 N.m W3: 0,4905 N x3: 0,04 m W3x3: 0,01962 N.m Total 0,14150925 Total 0,1407735 N.m N.m 6. DISCUSSION OF RESULTS a) The sum of the clockwise moments and the sum of the anticlockwise moments differ by a small amount. What is this difference in Nm? Why do they differ? The difference between the clockwise and the anticlockwise moment is 0,00073575 N.m. The weights seemed to in equilibrium but the calculus tells us that the moments are not equal; in this case, the only reason I can think of is the inaccuracy of materials. The rotation pivot must have exercised some kind of friction in the hole drilled in the middle of the metre rule; therefore preventing it to move freely under the weights of the different masses. b) This is not a very accurate experiment. Name one improvement would you suggest for the apparatus to improve accuracy. One of the many ways to improve the accuracy of this experiment would be to make sure the rotation pivot does not exercise any friction in the hole drilled in the middle of the metre rule. Once made frictionless, it must be able to move freely under the weights of the masses hung on it; therefore, allowing a much more accurate experiment. c) Could you do these calculations of the clockwise and anticlockwise moments without converting the masses to equivalent weights? If so, why? No, I couldn’t. A moment directly implies the present of a force, in this case weight. Which means I had to convert the masses to equivalent weights. d) The meter rule could be fixed in place at the fulcrum and the whole apparatus, with your weights attached, tilted to an angle θ to the horizontal (bench top). Would this action change the sum of the clockwise moments and the anticlockwise moments? Explain your answer. No, this action wouldn’t change anything because the weights would still be the same and the perpendicular distances would still concur in the same way as before. 7. CONCLUSION This experiment was meant to investigate the conditions required for the equilibrium of a pivoting beam which it did, in spite of the fairly negligible limitations in the accuracy of the materials used. CALCULATIONS: Submit your own analysis to this construction. Marks are awarded for clarity and neatness The answers are your own work…..copying of answers penalised There is no need to re-type these pages; no need for a title page, index etc