A person bites down on a hard nut held between the incisors
PHYSICS · Multi-part · Fermi University Physics · Biophysics & Medical Physics · Bioelectricity, the senses and the physics of the body · Bioelectricity, the senses and the physics of the body
Life at Thermal Energy, Ch Bones, muscles, blood and body size
Problem
A person bites down on a hard nut held between the incisors. The nut exerts a reaction force of 120N on the jaw at a point 7.0cm from the temporomandibular (jaw) joint. The masseter muscle, which closes the jaw, pulls at a point 3.0cm from the same joint, on the same side, perpendicular to the jaw. Treat the lower jaw as a rigid, weightless bar and all forces as perpendicular to it.
((a)) Taking moments about the jaw joint, find the force the masseter muscle must exert.
((b)) Find the force the jaw joint itself must supply.