2006-09-02 05:32:46 · 4 answers · asked by naughty coolaid 2 in Science & Mathematics ➔ Physics
The terminal velocity of an object falling towards the ground, in non-vacuum, is the speed at which the gravitational force pulling it downwards is equal and opposite to the atmospheric drag (also called air resistance) pushing it upwards. At this speed, the object ceases to accelerate downwards and falls at constant speed. An object moving downwards without power at greater than the terminal velocity (for example because it previously used power to descend, it fell from a thinner part of the atmosphere or it changed shape) will slow down until it reaches terminal velocity.
For example, the terminal velocity of a skydiver in a normal free-fall position with a closed parachute is about 195 km/h (120 Mph). It would take about 5.5 seconds to reach that speed. This speed increases to about 320 km/h (200 Mph) if the skydiver pulls in his limbs—see also freeflying. This is also the terminal velocity of the Peregrine Falcon diving down on its prey.
The reason an object reaches a terminal velocity is that the drag force resisting motion is directly proportional to the square of its speed. At low speeds the drag is much less than the gravitational force and so the object accelerates. As it speeds up the drag increases, until eventually it equals the weight. Drag also depends on the cross-sectional area. This is why things with a large surface area such as parachutes and feathers have a lower terminal velocity than small objects like bricks and cannon balls.
Mathematically, terminal velocity is described by the equation:
(see the site listed below for the equation)
2006-09-02 05:38:44 · answer #1 · answered by ted_armentrout 5 · 0⤊ 0⤋
It depends on gravity, atmospheric density and the object in question. The very definition of terminal velocity is the speed at which the air resistance balances out the gravitational acceleration for a given object. On Earth, a human has a terminal velocity of around 300 KPH. On the Moon, on the other hand, all objects would have a terminal velocity about the same as the speed of light, because there is essentially no atmosphere.
2006-09-02 12:37:50 · answer #2 · answered by Anonymous · 1⤊ 0⤋
54 m/s
2006-09-02 12:37:12 · answer #3 · answered by hayden160 3 · 0⤊ 1⤋
very fast
2006-09-02 13:13:04 · answer #4 · answered by Samvit 1 · 0⤊ 0⤋