Chapter 14, Problem 75PQ

Ruby, with mass 55.0 kg, is trying to reach a box on a high shelf by standing on her tiptoes. In this position, half her weight is supported by the normal force exerted by the floor on the toes of each foot as shown in Figure P14.75A. This situation can be modeled mechanically by representing the force on Ruby’s Achilles tendon with ${\stackrel{\to }{F}}_A$ and the force on her tibia as ${\stackrel{\to }{F}}_T$ as shown in Figure P14.75B. What is the value of the angle θ and the magnitudes of the forces ${\stackrel{\to }{F}}_A$ and ${\stackrel{\to }{F}}_T$?

FIGURE P14.75