Question

A parachutist after bailing out falls 50 m without friction. When parachute opens, it decelerates at
2 m/s2. He reaches the ground with a speed of 3m/s. At what height, did he bail out? (g = 9.81 m s2)

Answer 1

Answer:

Let's say height is "s" m.

The distance that that parachute has covered = 50m

Initial Velocity = 0

Acceleration = 9.8 m/sec2

v2 = u2+2as

v2 = 2*9.8*50 = 980

v2 = 980

v = root 980 = 14*Root 5 m/sec

Now Remaining Distance = s-50

Initial Velocity = 14*Root 5 m/sec

Acceleration = -2m/sec2

v2 = u2+2as

32 = 980-4(s-50)

9 = 980-4s+200

9 = 1180-4s

4s = 1171

s = 292.75 m