Wednesday, October 3, 2007

Forces : Hints

1. Three forces : two tensions and weight. Answers: 4.48N and 3.36N

2. Need to resolve tension before taking moments. Tensions have the same magnitude = 8.5N

3. Forces at the two supports : 5640N and 4414 N

4. Need to resolve tension before taking moments. Answer : 12.0N and Reaction at hinge can be obtained using pythagaros theorem and tangent of angle. Answer : 8.14 N and 18.6 degrees.

5. The tension in the strut should be called force by the strut on the shelf. Please ammend . The direction of the force F has to act upwards along the line of strut which angle can be found using trigonometry. Answer : F= 54.1 N and R at the hinge 72.0 N and 53 degrees.

6. Forces at support = 9250 N and 13750N.