WTF?!!
LuckySkreet:Gravity could care less
LuckySkreet: requires the objects "mass" to be included in the equation........this will give you the atmospheric resistance or "object drag".
Partially correct. Accurately important, as well.
Gravity is the MAIN force in action, in accelerated decent speed, shape is the deciding factor, as well as gravity, or lack there of. After terminal velocity has been achieved.
When first learning about how objects fall, usually just one force—gravity—is considered. Such a simplification only accurately describes falling motion in a vacuum. Galileo's principal.
Resistance, such as a parachutist... 50mps = 164 fps = 112 mph at which terminal velocity is achieved. This with belly down, and arms & legs outstretched.
Takes 10 seconds.
If his bag of concrete was in the shape of an air foil, it would fall faster, if the feathers were flattened out like a bed sheet, it would descend slower. Resistance is factored in when determining terminal velocity. In an atmosphere.
Drag increases with the square of the speed. So as the bag falls, we quickly reach conditions where the drag becomes equal to the weight, if the weight is small. When drag is equal to weight, there is no net external force on the object, and the vertical acceleration goes to zero. With no acceleration, the object falls at a constant velocity as described by Newton's first law of motion. The constant vertical velocity is called the terminal velocity.
If we have two objects with the same area and drag coefficient, like two identically sized spheres, the heavier object falls faster. This seems to contradict the findings of Galileo that all free falling objects fall at the same rate. But Galileo's principle only applies in a vacuum, where there is NO drag.
Any two objects fall at the same rate on the moon because, there is a vacuum, and no drag, and only gravity acting on the objects. In general, the same two objects fall at different speeds on the Earth and on Mars because of aerodynamic drag.
I can attest in person, that parachuting from and altitude of 12,000 feet you will achieve terminal velocity in 10 seconds. I can also attest that jumping from 55,000 feet you will achieve terminal velocity in 4 seconds.
112 mph was increased to classified speeds, during what some know as a "HALO" jump.
We called it immediate insertion. Traversing to countries with no fly zones & no other possible way for ordinary altitude intrusion. Drone chutes were deployed at 1500 feet to prematurely slow us down, to approximately 170mph. At 800 feet we dropped a 300 foot lanyard with 150lbs of gear, and prayed the main deployed in 3 seconds, giving us 5 seconds to decelerate to breakneck landing speed.
The pull on the legs and shoulders, was if two elephants were trying to rip your limbs off.
Then not to long ago, last year maybe, Felix Baumgartner became the fastest man in the atmosphere, without propulsion. A stupefying 729 MPH, after a 4 minute 14 second free fall, from 24.2 miles above the Earths surface. 3 chutes to slow him down. Chute lines 7 times thicker than normal, as to not rip themselves apart from the immediate deceleration, attached to a custom harness, as to not vivisect himself from rapid deceleration.
This man knows gravity, mass, and shapes, full effects on falling objects.
Ask him
Professor Whoopee out