Define terminal velocity

Answer 1

I used to do a bit of parachuting back in the 70s and terminal velocity was always reckoned to be about 120 mph (200 kph) achieved after about 12 seconds in free fall. But different objects will have different TVs, depending upon how aerodynamic they are. In physics, When an object is in a freefall,

and it reaches its terminal speed,

there is no net force,

and so its acceleration is zero. Going down, the direction of the air resistance is downwards, whereas that of the weight is upwards.

Going up, air resistance R and weight W are in the same direction. i.e. downwards.

By F=ma,

When an object is thrown vertically upwards,

at the instant its speed equals this terminal speed on the way up,

the magnitude of its acceleration is 20ms-2.

the direction is downwards. then by v = u + at,

you can easily calculate the terminal velocity in many different cases.

Answer 2

The http://wiki.answers.com/CONSTANThttp://wiki.answers.com/MAXIMUMhttp://wiki.answers.com/VELOCITYhttp://wiki.answers.com/REACHby a http://wiki.answers.com/BODYhttp://wiki.answers.com/FALLTHROUGHthe http://wiki.answers.com/ATMOSPHEREunder the http://wiki.answers.com/ATTRACTIONof http://wiki.answers.com/GRAVITY.

Answer 3

I will try and help you with this one.. terminal velocity is when a object falling has reached its fastest falling speed and will stay at this speed reaching a terminal velocity is due to friction in the air although you can't see them air particles offer resistance when passed through them untill the object changes its shape..eg aerodynamics...for example a sky diver will fall at about 80\100 mph...but if they dive down there will be less friction in the air to become faster until they reach 120mph which is the humans body terminal velocity and cannot physically go any faster

Answer 4

Terminal speed, formally called terminal velocity, is the speed at which an object falling through the air stops going any faster.

If the earth had no atmosphere/air when an object was dropped it would continue to go faster and faster until it hit the ground. But, the air pushes back on an object that's moving through it. If you stand in a strong wind it pushes on you, and the faster the wind is blowing the harder it pushes. Same thing when the wind blows the trees. In these examples the air is moving, you and the trees are trying to stand still, but it's the same as you or the tree moving through the air. This force on an object moving through air is called drag. When you first release an object from a great height the pull of gravity causes it to falling faster and faster, but if it falls long enough it reaches a speed where the drag of the air equals the gravity's pull and the object stops getting faster -- this speed it called terminal velocity, or as you asked, terminal speed.

The speed at which the downward pull of gravity is balanced by the equal and

upward opposing force of air resistance for a falling object.

Answer 5

A free-falling object achieves its terminal velocity when the downward force of gravity (Fg) equals the upward force of drag (Fd). This causes the net force on the object to be zero, resulting in an acceleration of zero, which means the object then falls at a constant speed. So, objects with little drag, like cannonballs have a much higher terminal velocity (about 220 miles per hour) than objects with lots of drag like skydivers falling flat (about 120 mph). But, of course, air gets denser as an object falls closer to the surface, so an object falling from a great height will first reach it's initial terminal velocity, then actually decelerate as the air drag continually increases, thus reducing the terminal velocity of the object as it falls.

More info (lots more!) here:

http://en.wikipedia.org/wiki/Terminal_velocityhttp://www.answers.com/topic/terminal-velocity-3#cite_note-0

Answer 6

Terminal velocity is the constant maximum velocity reached by a body falling through the atmosphere under the attraction of gravity. An object is moving at its terminal velocity if its speed is constant due to the restraining force exerted by the air, water, or other fluid through which it is moving.

Answer 7

In fluid dynamics an object is moving at its terminal velocity if its speed is constant due to the restraining force exerted by the air, water or other fluid through which it is moving.

A free-falling object achieves its terminal velocity when the downward force of gravity (Fg) equals the upward force of drag (Fd). This causes the net force on the object to be zero, resulting in an acceleration of zero.

Answer 8

Terminal velocity is the maximum speed an object will reach before air resistance pushing up on it and gravity pulling down on it equalize, thus making it's acceleration null.