Does a Plane Weigh More with a Bird Inside?

In summary, the bird exerts a downward force on the plane that is at least equal to its weight, but when the bird is moving it's wings 'up', if we assume that for at least an instant it is not pushing air downward, and it is freefalling you might say that for that instant it did not add weight to the plane.
  • #1
FSF17
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0
If a plane is flying along and inside the plane there is a little bird flapping away flying from front to back in the plane. Does the plane weigh anymore because the bird is inside it :confused: ?
 
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  • #2
Yes. When the bird is flying it is exerting a downward force at least equal to its weight.
 
  • #3
Ie, whether the bird is just sitting there or flying has no impact whatsoever on the flight of the plane.
 
  • #4
However, when the bird is moving it's wings 'up', if we assume that for at least an instant it is not pushing air downward, and it is freefalling you might say that for that instant it did not add weight to the plane.
 
  • #5
I agree with everyone, but I also agree with Decker. For example, if a jumbo-jet laden with 300 standing people(150 pounds average weight each) suddenly lifted their legs off the floor, a sudden weight reduction of 45,000 lbs. would occur. Of course, when they hit the floor, an increase would be in effect.
With respect to the bird scenario, weight cycling variations would be minimal and trivial, but would nonetheless occur given Decker's free-falling addition.
Lesson to be learned: Be certain the bird has a seat belt and it's tray is in an upright and locked position. :)
 
  • #6
pallidin said:
I agree with everyone, but I also agree with Decker. For example, if a jumbo-jet laden with 300 standing people(150 pounds average weight each) suddenly lifted their legs off the floor, a sudden weight reduction of 45,000 lbs. would occur. Of course, when they hit the floor, an increase would be in effect.
Except that for a 150 lbs person to jump, he has to exert a force on the floor of the plane, thereby "adding" to its weight. See:
https://www.physicsforums.com/showthread.php?t=16844
 
  • #7
If the people suddenly lift (not jump) then a force would not be exerted, but the force with which they lift must be greater than the pull of gravity
 
  • #8
quantum mechanic said:
If the people suddenly lift (not jump) then a force would not be exerted, but the force with which they lift must be greater than the pull of gravity
What is the difference between "lift" and "jump"?
 
  • #9
Chen said:
What is the difference between "lift" and "jump"?

A jump implies the application of a force to the ground or in this case the plane other than the force due to gravity.

Newton's 3rd law explains why a person is able to leave the floor by jumping: The interaction of the pushing of the leg against the floor of the plane.

A lift implies keeping the body stationary and simply, yet awkwardly, simultaneously making both legs not make contact with the plane. This also follows Newton's 3rd law of a force equal in magnitude oppositely directed; however, the upper body, not the plane is what pushes back. No force is initially applied to the plane other than the force due to gravity and the body begins to freefall, and as Decker stated, "if we assume that for at least an instant it is not pushing air downward, and it is freefalling you might say that for that instant it did not add weight to the plane."
 
Last edited:

1. Does a plane weigh more with a bird inside?

No, a plane does not weigh more with a bird inside. The weight of the bird is negligible compared to the weight of the entire plane and its cargo.

2. What is the weight of a standard bird?

The weight of a standard bird varies, but on average, a small bird weighs around 1-2 ounces, while a larger bird can weigh up to 20 pounds.

3. Can a bird's weight affect the fuel efficiency of a plane?

Yes, a bird's weight can affect the fuel efficiency of a plane, but the impact is very small. The amount of fuel used to transport a bird is negligible compared to the overall fuel consumption of a plane.

4. How does a plane accommodate for the weight of passengers and cargo?

Airplanes are designed to accommodate for the weight of passengers and cargo. The weight of the plane, including fuel, is evenly distributed throughout the wings, fuselage, and landing gear to ensure balance and stability during flight.

5. Can a bird cause a plane to crash due to its weight?

No, a bird cannot cause a plane to crash due to its weight. Airplanes are designed and tested to withstand various impacts, including bird strikes. In rare cases where a bird strike does cause damage to the plane, it is usually due to the bird being sucked into the engine, not its weight.

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