A Princeton prof. (mass = 70.0 kg), surprised by the large stopping force he calculates for jumping flat footed from a height of 0.12 m, decides to try the experiment. Calculate he deceleration (in g's) if he stops in a distance of 0.36 cm. (Do not try this. You could easily break an ankle!)

Answer 1

V at impact = sqrt (2 g H) = 1.53 m/s

If a is the deceleration after impact,
V = sqrt (2 a d), where d = 3.6*10^-3 m
a = V^2/(2 d) = 327 m/s^2
(33 g's)