When you take a bite out of an apple, you do about 19 J of work. Estimate the force and the power produced by your jaw muscles during the bite.

Question

anonymous · Answer

Open  your mouth wide. How many inches (or centimeters) apart do you think your teeth are?

anonymous · Answer

I would guess 2 to 3 inches.

anonymous · Answer

This is the distance the force of biting the apple is applied through. 

From the equation for work, $$W = F \cdot d$$

We know the work and the estimated distance. We can solve for the force a bite exerts.

anonymous · Answer

so that would be 0.0508 to 0.0762m ._.

anonymous · Answer

Yeah. That conversion looks right.

anonymous · Answer

For find the power, we realize that$$P = {W \over t}$$

We need to estimate how many seconds the act of biting the apple takes. What would you guess?

anonymous · Answer

so assuming that you open your mouth with the length of 2 inch, the force exerted would be 374N

anonymous · Answer

about 2 seconds?

anonymous · Answer

or 1.5

anonymous · Answer

That number looks right for force.

anonymous · Answer

That seems like a reasonable amount of time.

anonymous · Answer

This problem isn't so much about calculating work, power, and force as it is to understand these physics concepts. Use the reasonable assumptions we've talked about here and outline the choices you made with statements like, "I measured my open mouth to be 2 inches wide, which would be the distance through which the force of biting into an apple would act through."

anonymous · Answer

hmm okays. it looks simple after youve walked me through it. I got it. thanks for the help!

anonymous · Answer

Anytime! Good luck!