7. [12.2 Points] DETAILS MY NOTES ASK YOUR TEACHER Even when the head is held erect, as in the figure below, in center of mass is not directly over the principal point of support (the atlanto-occipital joint). F M The muscles at the back of the neck should therefore exert a force to keep the head erect. That is why your head falls forward when you fall asleep in the class. (a) Calculate the force (in N} exerted by these muscles. (Assume w = 49 N, .r1 = 4.9 cm, and r2 = 3.0 cm.) magnitude \\: N direction (b) What is the force (in N) exerted by the pivot on the head? magnitude E N direction Additional Materials L3 Reading Even when the head is held erect, as in the figure below, its center of mass is not directly over the principal point of support (the atlanto-occipital joint}. The muscles at the back of the neck should therefore exert a force to keep the head erect. That is why your head falls forward when you fall asleep in the class. (a) Calculate the force (in N) exerted by these muscles. (Assume w = 49 N, r1 = 4.9 cm, and r2 = 3.0 cm.) magnitude N upward (b) What is the f downward )y the pivot on the head? magnitude to the left direction to the right Additional Materials L3 Reading Submit