Flight with Basketball

Jaybird180

Jaybird180

Final Approach
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Jaybird180
An electric powered airplane is precisely trimmed for hands off S&L flight. Its sole occupant decides to dribble a basketball directly on the CG. In theory, will the aircraft's altitude vary during the bounce?
 
Do you mean the altitude of

  • the airframe,
  • or the altitude of the center of mass of the system consisting of the airframe, basketball, and everything else within the airframe?
If you mean the altitude of the airframe, here's what will happen.

  • Initially, as the occupant, who is essentially part of the airframe because of the seatbelt and harness, you are holding the basketball in your hands while the plane is in level flight.
  • Thereafter, either:

  • you release the ball so that it falls. At the moment of the release the mass of the airframe and all objects afixed to it becomes lighter. As a result, the plane will ascend.
  • or you throw the ball downward. The airframe will now ascend for two reasons (the reduced mass as mentioned above, and conservation of momentum arising from the impulse of throwing the ball downward).
  • Later, the ball impacts the airframe. This is essentially a collision. The ball will be deflected with an upward velocity as the result of this collision, and by conservation of momentum the airframe must be deflected oppositely with a downward velocity immediately after the collision.
So overall, in the sequence of impacts with your hand and the cabin floor, the altitude of the airframe will undergo a bouncing motion up and down, opposite that of the ball.
 
Last edited:
And may I add proportional to the masses of the airplane and basketball. The masses being significantly different will result in an insignificant movement of the airframe.
 
Sounds a lot like the "birds in the back of the truck" discussion regarding any change in the reading of the scales the truck is sitting on when the birds take off. Think "closed system" -- at the end of the day, the Law of Conservation of Energy applies, and the answer is "no change".
 
My bucket list does not include installing a treadmill in my plane.
 
Sluggo63 said:
I was thinking the same thing. Maybe so you don't have to account for the weight of the gas being burned?
Click to expand...

What about the gas emitted by the birds? I'm assuming the birds fart at some point...do birds fart?
 
Can't we talk about something more relevant like the Wright Bros were fraudsters or something more interesting such as steam?
 
just another reason why basketball sux.
 
If it was a player from my team, the airplane would go down.

Because when he would try to dribble, he would miss the floor altogether and hit and destroy some component of the aircraft necessary to continue the flight.
 
I saw a video of Bob Hoover dribbling a basketball while doing a barrel roll in a commander. It was incredible.
 
Jaybird180 said:
An electric powered airplane is precisely trimmed for hands off S&L flight. Its sole occupant decides to dribble a basketball directly on the CG. In theory, will the aircraft's altitude vary during the bounce?
Click to expand...

The answer is no....the zero carbon emissions from the AC will balance carbon emissions from the dribbler.

I live in California....carbon footprint is everything!!!:mad2::rofl::rofl::mad2::mad2:
 
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