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# Does gravity pull things down 32.2 feet per second?

Walsh

Lvl 1
2010-10-13 03:11:13

Absolutely Not.

Gravity is NOT a pulling Force. Gravity is a "Pushing" Force of Mass Expansion.

Earth Mass is Expanding at the Gravitational Acceleration rate of 9.808175174 m/s^2

In order to understand you must first accept the Mathematics on EinsteinElectricitydotcom because Math does not lie. Then you can move on to EinsteinGravitydotcom.

Acceleration due to gravity

No. There is a difference between speed (or velocity) and acceleration. They are, of course, related, but acceleration is the rate of change of velocity. When you are sitting in your car at a red light and the light turns green and you step on the gas (or accelerator!), your car accelerates from zero to some final velocity (hopefully not much more than the posted speed limit). Your speedometer clearly shows the change in velocity as the needle moves clockwise. The faster that needle moves, the greater the acceleration.

On Earth, objects do not fall at constant speed, as your question suggests. Gravity accelerates objects toward the center of the Earth at 32.2 ft per second per second (which can also be written as 32 ft/s2). In other words, an object's velocity will increase by 32.2 ft/s (or 9.8 m/s) for each second the object falls until it reaches its terminal velocity, which you can think of as a kind of speed limit. Terminal velocity is reached when air friction equally opposes the force of gravity. Different objects will have different terminal velocities, depending upon their shapes.

More discussion

Imagine you are on top of a tall building and holding a Bowling ball over the side of the building. At time t = 0 seconds, you let go of the ball. At that exact moment, the ball is traveling at 0 ft/s, but as the ball experiences gravity without your holding it, it starts to fall. After one second, the ball will be traveling 32.2 ft/s. After two seconds, it is traveling 64.4 ft/s, and after three seconds, it is traveling at 96.6 ft/s.

So you see that falling objects do not fall at the constant rate of 32.2 feet per second but actually accelerate -- that is, pick up speed -- at a rate of 32.2 feet per second per second.

Note: The equation of rectilinear motion can be found at:

Uh, Update: This article doesnt seem to mention "terminal velocity." Eventually, a falling bowling ball will not continue to pick up speed, it will reach Terminal Velocity, and stay at that speed. Terminal velocity is reached as the air resistance on a falling object approaches the momentum of the object. For example, as a bowling ball falls, gravity makes it accelerate at 32.2 feet per second. The bowling ball also hits air molecules, which slows it's acceleration. This is air resistance. As the bowling ball falls faster, more air molecules hit it per second. This is because the bowling ball travels a greater distance per second and passes through more air, and more air molecules. Eventually, the combined forces of all of the air molecules negate the acceleration of the bowling ball. At this point the bowling ball neither accelerates nor decelerates, it reaches an equilibrium. It will keep falling at a constant speed: its terminal velocity. If it were to somehow fall faster than its terminal velocity, the extra air molecules that hit it would actually slow it down until its terminal velocity was once again reached.

An object's velocity, then, is determined both by its weight and its shape relative to the ground. If an object is small, like a bowling ball, it does not pass through many air molecules per second, and must travel faster to hit enough air molecules per second to reach terminal velocity. If an object's surface area is large, like a parachute, it does not need to be traveling as fast in order to hit enough air molecules per second. yep your right agree subscribe

Wiki User

2010-10-13 03:11:13
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