Batman Begins: Fancy Grapple vs Flass' bodyweight

Earlier in the film, Fox states that Batman's new grapple can withstand up to 350lbs (158.8 Kg).
Let's see if it could actually withstand five stories of free-fall from a 250lb man (113.4 Kg)

F = m*a                                                                                         T = m*a                                                            a = Vf / change in time to slow to a stop                                                            Vf = time in free-fall * force of gravity                                                                                = 3.20s * 9.8m/s^2                                                                                       = 31.36m/s                                                             a = Vf / time taken to slow to a stop                                                                               a = (31.36m/s) / (1.1s)                                                                                   =  28.51m/s^2                                                                                         T = m*a                                                                                   = 113.4 * 28.51                                                                                       = 3232.93 N                                                                        = 329.89 Kg > 158.8 Kg limit

Conclusion:
We calculated that the force Flass put on that grapple would be too much based
off of specifications clarified earlier in the film.



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