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A parachutist whose weight is 75 kg drops from a helicopter hovering 2000 m above the ground and falls towards the ground under the influence of gravity. Assume that the force due to the air resistance is proportional to the velocity of the parachutist, with the proportionality constant k1 = 30 kg/sec when the chute is close and k2= 90 kg/sec when the chute is open. If the chute does not open until the velocity of the parachutist reaches 20 m/sec, after how many seconds will it be before the parachutist reach the ground? ( Take g = 9.81 m/sec2.)

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# Homework Help: Newtonian Mechanics

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