# Biting forces in a jaw

1. Nov 10, 2009

### Emethyst

1. The problem statement, all variables and given/known data
In a typical herbivore, the max magnitude of the force T (temporalis muscle) is 1/10 the max magnitude of the force M (masseter and pterygoideus muscles). a) Assuming that there is a force at the joint, would it be expected that the animal would exert the largest biting force near the front or back of the jaw? b) In a carnivore the max value of T is twice that of M. Would it be expected the max biting force to be extended further from or closer to the jaw joint than the herbivore?

2. Relevant equations
Net torque = 0, net force = 0

3. The attempt at a solution
I pretty much have no idea here :tongue:. I figured that for a) the biting force would be largest at the back of the jaw for the herbivore, while for b), the biting force would be further from the jaw joint for a carnivore than for a herbivore. The problem i'm having is understanding why this would be. Would torques be an explanation why the biting force is what it is, or is there other reasons as well, and do I even have the right response here for the questions? Any help would be greatly appreciated, thanks in advance.

2. Nov 10, 2009

### Andrew Mason

You will have to explain to me where these muscles attach to the jaw. This appears to be just a question about moments or torques but without knowing the physiology of jaw muscles it is hard to address the physics.

AM

3. Nov 10, 2009

### Emethyst

Ohh sorry for missing the picture, my apologies, here it is:

#### Attached Files:

• ###### Jaw.pdf
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4. Nov 11, 2009

### Emethyst

Anyone?

5. Nov 11, 2009

### Andrew Mason

I cannot tell where the joint is - the point about which the jaw turns. Is the joint at the bottom of that little jog on indentation on the right side?

AM

6. Nov 12, 2009

### Emethyst

I believe so, although it should not affect the answer though I do not think, since the question is not asking for an exact value. This is what is confusing me, i'm not sure how to relate the positions of the forces to the relative bite force created by the jaw.