Experiment 06

FORCES & VECTORS

ANALYSIS

Exercise A:  
1.    GRAPHICAL METHOD: On a plain sheet of graph paper, pick an origin in the middle of the sheet and lay out the +x-axis. Draw FORCE A to scale with its tail at the origin at with its angle laid off from the +x-axis with a protractor. You should choose a convenient scale such as 1N = 2 inches.

2.    Next, lay out FORCE B with its tail at the origin. Use a protractor to reproduce its angle also. Redraw FORCE B, without changing its orientation, so that its tail abuts the tip of FORCE A.

3.    Draw a vector from the origin to the tip of FORCE B--this is the RESULTANT. It has the same magnitude and is oriented 180° opposite to the EQUILIBRANT. Record the calculated values of the magnitude and the angle of the RESULTANT in cells B15:B16 and the magnitude of the EQUILIBRANT in cell C15 on the Worksheet. Make sure you reconvert from the inches scale back to newtons.

4.    If the RESULTANT’S angle is less than 180°, add 180° to it and enter the result under EQUILIBRANT DIRECTION in cell C16. If the angle is greater than 180°, subtract 180° from it and enter the result in cell C16.

5.    Compare the measured and calculated values of both magnitude and direction of the EQUILIBRANT. Find the Percentage Difference between the two values in each case, and enter in cells D15 and D16.

6.COMPONENT METHOD: Compute the x- and y-components of FORCE A, FORCE B, and the EQUILIBRANT, and record in cells B20:D21 on the Worksheet.
BE CAREFUL about the algebraic signs of the components.

7.     Add up the components of FORCE A and FORCE B separately to obtain the x-component and the y-component of the RESULTANT, and enter in cells E20:E21.

8.    Copy the magnitude of the EQUILIBRANT in cell D23 from cell D10.

9.     From the components of the RESULTANT, calculate the MAGNITUDE and enter its value in cell E23.

10.    Compare the MAGNITUDE that you have computed with the MAGNITUDE of the EQUILIBRANT. Find the PERCENTAGE ERROR and enter it into cell E24.
 

 Exercise B: 1.    GRAPHICAL METHOD: On another plain sheet of graph paper, pick an origin in the middle of the sheet and lay out the +x-axis. Draw FORCE A to scale with its tail at the origin at with its angle laid off along the +x-axis (0°). You should choose a convenient scale such as 1N = 2 inches.

2.    Next, lay out FORCE B with its tail at the origin. Use a protractor to reproduce its angle. Redraw FORCE B, without changing its orientation, so that its tail abuts the tip of FORCE A. Repeat the same procedure for FORCE C, abutting its tail to the tip of FORCE B.

3.    Draw a vector from the origin to the tip of FORCE C--this is the RESULTANT. It has the same magnitude and is oriented 180° opposite to the EQUILIBRANT. Record the calculated values of the magnitude and the angle of the RESULTANT in cells B34:B35 on the Worksheet. Make sure you reconvert from the inches scale back to newtons.

4.    If the RESULTANT’S angle is less than 180°, add 180° to it and enter the result under EQUILIBRANT DIRECTION in cell C35. If the angle is greater than 180°, subtract 180° from it and enter the result in cell C35.

5.    Compare the measured and calculated values of both magnitude and direction of the EQUILIBRANT. Find the Percentage Difference between the two values in each case, and enter in cells D34 and D35.

6.    COMPONENT METHOD: Compute the x- and y-components of FORCE A, FORCE B, FORCE C, and the EQUILIBRANT, and record in cells B39:E40 on the Worksheet.
BE CAREFUL about the algebraic signs of the components.

7.     Add up the components of the three individual forces separately to obtain the x-component and the y-component of the RESULTANT, and enter in cells E45:E46.

8.     Copy the magnitude of the EQUILIBRANT in cell D48 from cell E29.

9.    From the components of the RESULTANT, calculate its MAGNITUDE and enter the value in cell E48.

10.    Compare the MAGNITUDE that you have computed with the MAGNITUDE of the EQUILIBRANT. Find the PERCENTAGE ERROR and enter it into cell E49.

11.    Hand in the Worksheet and the two vector plots with your lab report.