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A remarkable
species of ants known as “trap-jaw ants” have
a pair of jaws (mandibles) that can open to 180 A group at
Berkeley‡ took high-speed videos
of the ants jumping. (The frame rate was one frame every 20 microseconds – 2 x 10 Let’s use these data to get an idea of the forces involved. A. One mandible
(the one represented by the open circles in the graphs) changes
its speed from about 40 m/s (that is NOT a typo) to -30 m/s in
about 40 μs (4 x 10 |

B. If the force from
the two mandibles is exerted on an object in front of the ant, the
ant will be thrown backward or upwards. If the mass of the ant is 12 mg (1.2 x 10^{-5} kg),
with what speed will the ant be thrown backwards?

C. If the force is exerted down, about how high will the ant be thrown in the air? (Simplify the calculation by ignoring air resistance and assuming the ant is pushing straight down the entire time.)

†Wikipedia, Odontomachus, accessed 11/16/10.

‡S. N. Patek et al., Proceedings of the National Academy of Sciences103:34 (8/22/2006) 12787-12792

Page last modified December 28, 2010: PE42