A domestic cat extends its hind legs by about before leaving the ground with a…
PHYSICS · Multi-part · Fermi University Physics · Mechanics & Dynamical Systems · Biophysics & Medical Physics · Momentum, energy and conservation laws
Forces, Machines and Signals, Ch Bones, blood and body size
Problem
A domestic cat extends its hind legs by about d=0.30m before leaving the ground with a vertical take-off speed of about v=3.0ms−1, both from video measurement. Vertebrate skeletal muscle can shorten fully in about 0.1 to 0.2s without needing an elastic catapult mechanism. Air resistance is ignored.
((a)) State the assumptions needed, then estimate the height the cat rises after leaving the ground and the time it spends extending its legs during take-off.
((b)) Decide whether the cat's jump can plausibly be powered by direct muscle contraction, or whether (as in a flea) it must store energy in an elastic element first.
((c)) Compare the estimated height with a measured standing vertical jump height for a domestic cat of about 0.5m.