Is Free Fall Possible Without Air Resistance?

In summary, the conversation is discussing whether an object in free fall is still affected by air resistance and whether free fall is possible without air resistance. It is noted that when an object is falling through air, it experiences weight, friction, and upthrust as forces. However, when in free fall, the resultant force is zero. The example of geosynchronous satellites is also mentioned as being in free fall without air resistance. The conversation also touches on the definition of free fall and how it can be subjective.
  • #1
hydrogen
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Hey guys,

when an object is free falling, is it still under the effects of air resistance? If it was not under the effects (an environment without air resistance) is free fall possible? (I am looking for an argument that it is under the effects of free fall but all replies will be taken into consideration)
 
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  • #2
When a body is falling through the air there are three forces acting on it, Weight(W), Friction(F) and upthrust(U).
The resultant force is given by [itex]F_R=W-U-F[/itex], when in free fall the resultant force is zero. So then the air resistance is still there but the weight is numerically equal to the sum of the air resistance and upthrust.
 
  • #3
If someone is free-falling off a bridge, there is air resistance. Geosynchronous satellites are in free-fall, and there is no air resistance.

Sounds like a discussion about a definition rather than physics?
 
  • #4
Yes, it is a discussion about a definition. The technical physics definition is falling where the only force acting on you is gravity. So that means jumping out of a plane doesn't qualify. But definitions are a matter of consensus, so the dictionary has that one in there too.
 

FAQ: Is Free Fall Possible Without Air Resistance?

What is free fall and how does it differ from regular falling?

Free fall is the motion of an object when it is only under the influence of gravity. This means that the object is not being pushed or pulled by any other forces. In contrast, regular falling involves air resistance and other forces that may affect the object's motion.

How does air resistance affect free fall?

Air resistance, also known as drag, is a force that opposes the motion of an object through the air. In free fall, air resistance can slow down the object and prevent it from reaching its maximum velocity. This is because as the object falls, it pushes against the air molecules, which creates a force in the opposite direction of its motion.

Does air resistance always slow down an object in free fall?

Yes, air resistance will always slow down an object in free fall. However, if the object is falling through a vacuum where there is no air, then there will be no air resistance and the object will continue to accelerate until it reaches its maximum velocity.

How does the surface area of an object affect its free fall?

The surface area of an object can greatly impact its free fall due to air resistance. Objects with a larger surface area, such as a parachute, will experience more air resistance and therefore fall at a slower rate compared to objects with a smaller surface area, such as a pencil.

Can an object reach a constant speed in free fall?

No, an object cannot reach a constant speed in free fall. This is because the force of gravity will continue to accelerate the object until it reaches its maximum velocity, also known as terminal velocity. At this point, the force of gravity and the force of air resistance are equal and the object will fall at a constant speed.

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