Question

The human mandible (lower jaw) is attached to the temporomandibular joint (TMJ). The masseter muscle is largely responsible for pulling the mandible upward when you are talking or eating. It is attached at a horizontal distance of about 3.2 cm from the TMJ. If this muscle exerts a force of 222 N when you bite, what is the force your incisors exert? The horizontal distance from the TMJ to your incisors is 6.9 cm. Assume that both forces are vertical.

Answer 1

Answer:

102.95652 N

Explanation:

$F_1$ = Force on muscle = 222 N

$F_2$ = Force on incisor

$r_1$ = Distance of muscle = 3.2 cm

$r_2$ = Distance to incisor = 6.9 cm

Here the torque in the system is conserved so we have

$F_1r_1=F_2r_2\\\Rightarrow F_2=\dfrac{F_1r_1}{r_2}\\\Rightarrow F_2=\dfrac{222\times 3.2}{6.9}\\\Rightarrow F_2=102.95652\ N$

The force the incisors exert is 102.95652 N