Share
Explore BrainMass

# Analysis of dynamics of parachute fall

A parachutist whose mass is 75kg drops from a helicopter hovering 4000m above the ground and falls towards the earth under the influence of gravity. Assume that the force due to air resistance is proportional to the speed of the parachutist with proportionality constant k_1=15kg/s when the chute is closed and with constant k_2=105kg/s when the chute is open. If the parachute is not opened until a minute after the parachutist has left the helicopter, after how many seconds will the parachutist land on the ground?

#### Solution Preview

From the information use Netwons 2nd law to derive an equation for the net force acting on the parachutist, this will be the force of gravity x his mass minus the air drag and equate this to mass*acceleration.

You will then get a differential equation which you can solve for his velosity at any time

Integrate ...

#### Solution Summary

Using differential equations the fall of a parachutist under known conditions is analysed and the time taken for the parachutist to hit the ground determined. The following is provided..

A parachutist whose mass is 75kg drops from a helicopter hovering 4000m above the ground and falls towards the earth under the influence of gravity. Assume that the force due to air resistance is proportional to the speed of the parachutist with proportionality constant k_1=15kg/s when the chute is closed and with constant k_2=105kg/s when the chute is open. If the parachute is not opened until a minute after the parachutist has left the helicopter, after how many seconds will the parachutist land on the ground?

\$2.19