A parachutist whose mass is 80 kg drops from a helicopter hovering 1000 m above the ground and falls toward the ground under the influence of gravity. Assume that the force due to airresistance is proportional to the velocity of the parachutist, with the proportionality constant b, = 30 N-sec/m when the chute is closed and b, = 90 N-sec/m when the chute is open. If the chutedoes not open until the velocity of the parachutist reaches 20 m/sec, after how many seconds will the parachutist reach the ground? Assume that the acceleration due to gravity is 9.81 m/ sec.

given : mass m =80 kg V0 = 0 (initial velocity) b1 = 30 Ns/m (chute is…

Answered: A parachutist whose mass is 80 kg drops…

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