In: Physics
In February 1955, a paratrooper fell 370 m from an airplane without being able to open his chute but happened to land in snow, suffering only minor injuries. Assume that his speed at impact was 60 m/s (terminal speed), that his mass (including gear) was 71 kg, and that the magnitude of the force on him from the snow was at the survivable limit of 1.2
Initial velocity, u = 0
Final velocity, v = 60 m/s
Mass of person along with gear, m = 71 kg
The force exerted by snow, F = 1.2 * 10^5 N = 120000 N
We have a formula F = ma
a = F/m = 120000/71 = 1690.14 m/s^2
Again we have a formula, 2as = (v^2 - u^2)
from this, s = (v^2 - u^2)/2a = 1.065 m
The impulse on the person from the snow = mv - mu = mv - 0
= mv = 71 * 60 = 4260 kg m/s