How much Ke should she have at 328 m?
m g h = 71(9.81)(1370-328) Joules
How much Ke does she actually have?
(1/2) m v^2 = (1/2)(71)(68)^2
The difference is how much work is done by air friction.
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At 328 meters she has a total energy of
m g 328 + (1/2) m (68)^2
At the ground she has a total energy of
0 + (1/2)m (2.8)^2
The difference is work done by the chute.
A 71 kg skydiver jumps out of a plane at an altitude of 1370m. She reaches terminal velocity of 68m/s. She opens the parachute at an altitude of 328m, and lands with a speed of 2.8m/s.
a)How much (negative) work is done by air resistance before she opens the chute?
b)How much is done by the parachute?
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