A student bends her head at 40.0o from the vertical while intently reading her physics book, pivoting the head around the upper vertebra (point P in the figure below(Figure 1) ). Her head has a mass of m = 4.70 kg (which is typical), and its center of mass is 11.0 cm from the pivot point P. Her neck muscles are x = 1.55 cm from point P, as measured perpendicular to these muscles. The neck itself and the vertebrae are held vertical.
Find the tension in her neck muscles.
How do I set up the formula in regards to a free body diagram?
