Question

A hemispherical parachute made of an air-impervious material is 8.0(m) in diameter. The mass of the parachute and load combined is 80(kg). Assume the drag coefficient of 1.42 is based on frontal area facing flow and the viscosity of air is 1.8x10^-5(PI).

a. How fast will the parachute descend in still air assuming pressure drag dominates?

b. Calculate the Reynolds number based on these two calculations and determine whether pressure drag or viscous drag dominates.

c. How far would an object with no drag have to fall to reach this same speed as it accelerates from rest? i.e., Landing with a parachute will involve about the same impact as would a downward free jump of this distance.

Answer 1