Surviving a Freefall: Calculating the Impulse on a Paratrooper Landing in Snow

[dominus96]

Homework Statement

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 80 kg, and that the force on him from the snow was at the survivable limit of 1.2*10^5 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

delta P = F*t
F=ma?

The Attempt at a Solution

I have no clue, I've never seen a problem like this before...

 

[catkin]

You didn't search very hard: www.physicsforums.com/showthread.php?t=196991

 

[rl.bhat]

Paratrooper's mass and treminal velocity is given. Find his KE when he touches the ground. Finally he stops. Change in KE = Force X Displacement.

 

[aq1q]

lol.. this type of problem again.. just look at that thread www.physicsforums.com/showthread.php?t=196991

 

[dominus96]

I found KE, but what does that have to do with impulse? I thought impulse was change in momentum?

 

[aq1q]

impulse is mV1-mV2

 

[aq1q]

but KE will tell u what velocity the man lands at the snow

 

[dominus96]

mv1 - mv2...is that like P1 - P2? (P stands for momentum)

 

[Vidatu]

Yes. Now that you have kinetic energy, you have everything you need to solve this.