Question

A patient with a dislocated shoulder is put into a traction aparatus and .The pulls A and B have equal magnitudes and muat combine to produce an outward traction force of 5.60N on the patient arm.How large should these pulls be?

Answer 1

The traction apparatus used for correcting dislocated shoulders may look like this one on the picture below:

So, since the outward traction force must be 5.6 N, it must be provided by the forces A and B directed at some angle. Using horizontal projections we get for equal forces A and B

$$5.6=A\text{cos}32^\circ+B\text{cos}32^\circ=2F\text{cos}32^\circ,$$

$$F=\frac{5.6}{2\text{cos}32^\circ}=3.3\text{ N}.$$