A skydiver of weight 84kg jumps from a plane 3300m above the ground. They initially free fall for a period of seconds then deploy a parachute to allow them to land on the ground with a safe landing speed of 6m/s.
The skydiver has drag coefficient of 0.5, based on a frontal area of 0.4m^2, whilst the parachute has drag coefficient 1.2 based on area of 40m^2. The parachute takes 5 seconds to open during which time the drag coefficient is assumed to vary linearly between 0 and 1.2
Determine a velocity versus time graph of their descent, and estimate the maximum freefall distance that would allow a safe landing speed of 6m/s.