In february 1955, a paratrooper fell 1200 ft from an
airplanewithout being able to open his chute but happened to land
in snow, suffering only minor injuries. assume that his speed at
impact was56 m/s (terminal speed0, that his mass (including gear)
was 85 kg, and that the force on him from the snow was at the
survivable limitof 1.2 x 10 ^ 5 n. what is the minimum depth of
snow that wouldhave stopped him safely?

is the minimum depth of snow for survivable stopping.

Explanation:

Given:

Firstly, we calculate the deceleration caused in the snow:

Now, using equation of motion:

....................(1)

where:

v = final velocity of the body after stopping

u = initial velocity of the body just before hitting the snow

a = acceleration of the body in the snow

s = distance through in the snow

Putting respective values in eq. (1)

speed of light in vacuum is 300,000 km/s

speed of light in other mediums is given by the expression v = c/n, where c is the speed of light in vacuum and n is the refractive index of medium.

for the first medium v = 200,000 km/s

  so, refractive index of medium = 300000/200000 = 1.5

    1.5 refractive index is usually for glass. so first medium is glass.

for the second medium v = 250,00 km/s

so, refractive index of medium = 300000/250000 = 1.2

    1.2 refractive index is usually for water. so second medium is water.

for the third medium v = 0 km/s

so, refractive index of medium = 300000/0 = ∞

    ∞ refractive index is usually for opaque mediums. so third medium is opaque medium.