[winkosmosis]

Originally Posted by wyatt

If I understand parachutes correctly, they work by increasing the surface area. The shape of the parachute is secondary and works twofold. The cup shape is better at catching air, but that takes me to the second point, it has to be cup shaped to stay inflated, i.e. it has to be inflated to maintain the surface area... If you could make a parachute that was flat and rigid of equal area, (and weight and was aerodynamically stable) you would fall faster, but it would still slow you down almost as well. I will argue that the surface area is king here. So I will agree, the front grill of a car with the grill blocked from behind is parachute shaped, but not of a greater area.

A parachute has more air resistance than a flat sheet with the same frontal area.