An airplane pilot fell 365 m afterjumping from an aircraft without his parachute
ID: 1724620 • Letter: A
Question
An airplane pilot fell 365 m afterjumping from an aircraft without his parachute opening. He landedin a snowbank, creating a crater 1.3 mdeep, but survived with only minor injuries. Assuming the pilot'smass was 75 kg and his terminal velocitywas 50 m/s, estimate the following.(a) the work done by the snow in bringing him to the rest (b) the average force exerted on him by the snow to stophim (c) the work done on him by the air resistance as he fell
An airplane pilot fell 365 m afterjumping from an aircraft without his parachute opening. He landedin a snowbank, creating a crater 1.3 mdeep, but survived with only minor injuries. Assuming the pilot'smass was 75 kg and his terminal velocitywas 50 m/s, estimate the following.
(a) the work done by the snow in bringing him to the rest (b) the average force exerted on him by the snow to stophim (c) the work done on him by the air resistance as he fell
Explanation / Answer
a) Using his terminal velocity, we can say that the pilot's Kineticenergy at impact was KE = (1/2)(75kg)(50m/s)2 = 93750 J The work done to stop him must equal this energy. W = 93750 J b) Average Force: F = W/d = 93750J/1.3m = 72115.38 N c)The work done by air resistance is equal to the energy lostduring the fall. At the beginning he has just potential energy, andat the bottom, just kinetic. The difference between them is thework. PE - KE = W (m)(g)(h) - (1/2)(m)(v2) = W (75)(9.8)(365) - (1/2)(75)(502) = 174525 J