Organismal Physiology Lecture No. 21: Max Forces In Animals
Thursday November 22 , 2012
-Animals are much faster than Man. And in addition to running, animals exert all kinds of forces on the
environment such as in swimming, flying, jumping, and in pushing and punching.
Equations To Consider For Maximum Forces In Animals:
Fin S x (A x sin 2θ) F out F inMA Mechanical Advantage (MA) = Lever / Lev1r 2
-An increase in body mass (bigger) produces greater force. In lever mechanics, greater mechanical
advantage is demonstrated (a greater load can be lifted) if the lever is longer on the side that is doing
the lifting. An increase in mechanical advantage allows you more force (mostly observed in vertebrates
in terms of biting). Why is there a negative slope? Because there is a relative loss of force as body mass
increases and surface area decreases (forces scales to A and doubling cross-sectional area increases F).
Maximum forces are proportional to 2/3 of body mass. Certain constraints operate upon forces in the
animal kingdom that crabs are somehow able to overcome e.g. nipping point in crabs.
Measuring Claw Force In Crabs:
-Certain constraints operate upon forces in the animal kingdom that crabs are somehow able to
overcome e.g. nipping point in crabs. Crabs can grasp a strain gauge reliably with maximum force day
after day. It is this nipping by crabs that can break into the constrained area of a crab.
Reasons For Extreme Crab Strength: