torques

Your 'torques' report has been received. Scroll down through the document to see any comments I might have inserted, and my final comment at the end.

Your optional message or comment:

Positions of the three points of application, lengths of systems B, A and C (left to right), the forces in Newtons exerted by those systems, description of the reference point:

.8,8.0,12.1

7.7,7.8,8.5

.78,1.82,1.9

left side of the horizontal line

The first and last were obtained from matching the cm in length to the corresponding N on that certain graph, the middle one since there was two rubber band these were added together.

Net force and net force as a percent of the sum of the magnitudes of all forces:

-.78

17.3

Moment arms for rubber band systems B and C

7.4,4.2

Lengths in cm of force vectors in 4 cm to 1 N scale drawing, distances from the fulcrum to points B and C.

3.12,7.28,7.6

7.4,4.2

Torque produced by B, torque produced by C:

-7.6,+5.7

Net torque, net torque as percent of the sum of the magnitudes of the torques:

-1.9

14.3

-7.6 + 5.7=-1.9, then divide this by 7.6+5.7=13.3, multiply by 100 to get 14.3

Forces, distances from equilibrium and torques exerted by A, B, C, D:

1.86,0,0

-1.47,1.7,-2.5

-1.00,9.4,-9.4

.13,13.5,1.76

The sum of the vertical forces on the rod, and your discussion of the extent to which your picture fails to accurately describe the forces:

-.48

The forces should total to 0 since there is no movement of the rod.

Net torque for given picture; your discussion of whether this figure could be accurate for a stationary rod:

6

no the value should be 0 for a stationary rod

For first setup: Sum of torques for your setup; magnitude of resultant and sum of magnitudes of forces; magnitude of resultant as percent of sum of magnitudes of forces; magnitude of resultant torque, sum of magnitudes of torques, magnitude of resultant torque as percent of the sum of the magnitudes:

-10.14

-.48,4.46

10.8

-10.14,13.66,74

For second setup: Sum of torques for your setup; magnitude of resultant and sum of magnitudes of forces; magnitude of resultant as percent of sum of magnitudes of forces; magnitude of resultant torque, sum of magnitudes of torques, magnitude of resultant torque as percent of the sum of the magnitudes:

-6.13

.5,4.54

11

-6.13,28.01,

22

In the second setup, were the forces all parallel to one another?

10

Estimated angles of the four forces; short discussion of accuracy of estimates.

90,100,100,100

The placement of the rubber bands and hooks was difficult so I suspect the results are not extremely accurate.

x and y coordinates of both ends of each rubber band, in cm

1.2,2,2.1,10.5

7.6,15.8,5.8,23.9

16.3,10.5,21.7,3.7

Lengths and forces exerted systems B, A and C:.

8.5,1.86

8.3,3.55

8.7,2.53

Measured the first value in cm then found the coordinate force value that matched on the graph.

Sines and cosines of systems B, A and C:

-90,-84.0

77.4,-77.5

-51.4,51.6

Magnitude, angle with horizontal and angle in the plane for each force:

8.5,84.0,264

8.1,-77.5,102.5

8.7,-51.55,308.5

x and y components of sketch, x and y components of force from sketch components, x and y components from magnitude, sine and cosine (lines in order B, A, C):

-5.6,12.7,-1.4,3.18,-.768,3.46

-.5,-7.1,-.125,-1.78,-.194,-1.86

7,-14,1.75,-2,1.57,-1.98

Sum of x components, ideal sum, how close are you to the ideal; then the same for y components.

.608,0,.608

-.38,0,-.38

Distance of the point of action from that of the leftmost force, component perpendicular to the rod, and torque for each force:

0,-1.86,0

6.4,3.46,22.14

15.11,-1.98,-29.92

Sum of torques, ideal sum, how close are you to the ideal.

-7.78,0,7.78

How long did it take you to complete this experiment?

5 hrs

Optional additional comments and/or questions:

Your work on this experiment looks good.

Please let me know if you have any questions related to this orientation assignment.