) A friend of yours complains that he often has lower back pain. One day while he picks up a package, you notice he bends at his hips rather than keeping his back straight and bending his knees. Assume he pivots at the hips so that his spine is horizontal. His back muscles then exert a force at 48 cm away from the hips at 13.5 degrees above the horizontal (directed slightly up and to the left in the picture shown). The weight of his upper body is 560 N, and his center of mass is 38 cm from the hips. Draw a force diagram of the spine. What total force is exerted by the back muscle when he picks up a 10 kg package at 82 cm from the hips? Extra credit: Find the force exerted by the hips on the spine/pelvis

Explanation:

Please see the figure attached for free body diagram .

Taking torque about the hip joint ,

560 x 38 + 100 x 82 = F sin13.5 x 48

21280 + 8200 = 11.2 F

F = 2632.14 N .

Force exerted by the hip on the spine = 2632.14 N .

neither accurate nor precise.

this is an example of "committed" time.

committed time, as contracted time, takes need over essential and available time since it is seen as profitable work. it alludes to the time allotted to keep up a home and family. at the point when a man is commuting using committed time this individual may feel that the drive is an obligation to family, for example, strolling youngsters to class or driving a mate to work. contracted and committed time clients may feel that their commute could really compare to the commute of important or leisure time clients on the grounds that their commute is profitable work. in this manner, they might be more disposed to pick a mechanized method of movement.