How Deep Must Snow Be to Safely Stop a Falling Paratrooper?

[patelkey]

Homework Statement

A paratrooper fell 375 m from an airplane without being able to open his chute. Assume that his speed at impact was 52 m/s (terminal speed), that his mass (including gear) was 85 kg, and that the force on him from the snow was at the survivable limit of 1.2 multiplied by 105 N.

a.) What is the minimum depth of snow that would have stopped him safely?

b.)What is the magnitude of the impulse on him from the snow?

Homework Equations

impulse is integration of force with respect to time

The Attempt at a Solution

 

[Soveraign]

Homework Statement

A paratrooper fell 375 m from an airplane without being able to open his chute. Assume that his speed at impact was 52 m/s (terminal speed), that his mass (including gear) was 85 kg, and that the force on him from the snow was at the survivable limit of 1.2 multiplied by 105 N.

a.) What is the minimum depth of snow that would have stopped him safely?

b.)What is the magnitude of the impulse on him from the snow?

Homework Equations

impulse is integration of force with respect to time

The Attempt at a Solution

The first can be thought of as a conservation of energy problem. Consider how much work it would take to stop the person. (this assumes the distance he falls through the snow adds a negligible amount of potential energy... even if it doesn't you can still solve this in a similar way).

For part b, consider that impulse and momentum have the same units... how much impulse is required to stop X amount of momentum?