Does a fly on an airplane add weight to the airplane if the fly never lands?

yes, because flies have intertia aka mass

Yes. The fly has to push air down, basically, to stay up. Like a helicopter, the air surges down and hits the floor of the plane and increases its weight.

If you took a produce scale, which is kind of sensitive and has a that big bowl hanging from it, and held it up under a hovering helicopter, it would register weight from the gasses pushing against the surface of the bowl.

PS. I don't know what the hell I am talking about really but it seems to make sense to me.

Yes, anything on or in the plane adds weight.

Doesn't make a difference if it's in the air.

Same for a bubble, bird, etc........

Yes. How do you think the fly is staying up in the air? It is not because the fly is made of helium or is weightless. Its wings are exerting a downward force equal to its weight; this will be reflected as an increase in the weight of the plane equal to the force exerted downward by the fly. However if it accelerates upwards or downwards inside the plane, the weight will in fact temporarily change (although the mass will always remain constant).

Yes, it does. Similarly:

Suppose a guy weighs 196 pounds and he's carrying three two-pound balls.

[Insert juvenile smutty joke here. Okay? You through? Good, let's go on...]

He comes to a bridge that allows a maximum weight of exactly 201 pounds--any weight greater than that will cause it to fall. He decides that he'll juggle the balls, so he's never totaling more than 200 pounds at one time: one of the balls is always in the air.

[Insert second joke here. Damn, I knew I should have waited until junior high was back in session.]

Yet he takes one full step on the bridge, it fails, and he falls to his death. Why?

Ah I see this was answered before I posted. So to contribute I'll pose another (more difficult) question: there are two bikers travelling at the same speed. One is biking alone, the other is followed closely by another cyclist drafting off of him. Do the two bikers have to exert the same amount of energy to keep going at the same speed? (FYI I don't know the answer)

michael furey wrote:

there are two bikers travelling at the same speed. One is biking alone, the other is followed closely by another cyclist drafting off of him. Do the two bikers have to exert the same amount of energy to keep going at the same speed? (FYI I don't know the answer)

In a vacuum, yes. In the real world, no.

michael furey wrote:

Ah I see this was answered before I posted. So to contribute I'll pose another (more difficult) question: there are two bikers travelling at the same speed. One is biking alone, the other is followed closely by another cyclist drafting off of him. Do the two bikers have to exert the same amount of energy to keep going at the same speed? (FYI I don't know the answer)

I assume by "two bikers" (there are three), you mean the two out front. All things being the same (bikes, body weight, etc.)there should be no difference. The drafter is behind the cyclist and not physically connected to him. Once the air passes him, the air friction or wind resistance created by the second cyclist means naught to the first.

fyth wrote:

Yes, it does. Similarly:

Suppose a guy weighs 196 pounds and he's carrying three two-pound balls.

[Insert juvenile smutty joke here. Okay? You through? Good, let's go on...]

He comes to a bridge that allows a maximum weight of exactly 201 pounds--any weight greater than that will cause it to fall. He decides that he'll juggle the balls, so he's never totaling more than 200 pounds at one time: one of the balls is always in the air.

[Insert second joke here. Damn, I knew I should have waited until junior high was back in session.]

Yet he takes one full step on the bridge, it fails, and he falls to his death. Why?

Please explain this one to me. It seems to me that he has to exert more than two pounds of force on the ball to make it leave his hand, and the ball exerts more than two pounds of force when landing back in his hand. But, only one is in his hand at a time when juggling, so while he'd be certainly over 198 lbs( his weight + balls weight + extra force), it's dependent on how high he throws the ball (how much extra force is applied) to be certain that he's totaling over 200 lbs.

It is not dependent on how high he throws the balls. If he does throw them higher, he will have to exert even more force to accelerate them (and he will also be subject to more force when he catches them again). Although, interestingly, the amount of force he is applying onto the bridge will fluctuate (I don't know much about juggling, but at a moment when all 3 balls are in the air, only 195 lbs of force will be applied to the bridge. I'd guess with pretty strong conviction that the average force he is exerting on the bridge over time is 201 lbs though).

Forget the plane. Does a plane who flies over a bridge add weight to it? Now enclose the plane in the bridge so as it can still move freely, it's the same thing.

I believe I misread and thought that two balls were constantly in the air, not one.

Redundancy wrote:

Forget the plane. Does a plane who flies over a bridge add weight to it?

yes

Interestingly he will still probably break the bridge if he doesn't have any balls at all (haha) because of the increase in weight when his feet exert force on the bridge when he pushes off, especially if he decides to run across. He will also weigh less when his leg begins to accelerate downward with each step at the highest arc of his foot.

Is the fly on a treadmill?

Did the plane take off from a treadmill?

fyth wrote:

Yes, it does. Similarly:

Suppose a guy weighs 196 pounds and he's carrying three two-pound balls.

[Insert juvenile smutty joke here. Okay? You through? Good, let's go on...]

Jeez, isn't ANYBODY going for a snarky Caster Semenya reference?

jeff goldblum wrote:

If there is a fly buzzing around the inside of a flying airplane, but it never lands on anything inside of the airplane. Does the fact that the fly is inside of the flying airplane increase the weight of the airplane by the weight of the fly?

Lol, lol, lol!

Seriously,

this is a great question.

Wrong. Having a cyclist behind you reduces the low pressure drag while having a cyclist in front you reduces the high pressure drag. Cycling in a line helps those in front and those behind. The most helped are those who are in the middle of the line.

Whaaat? wrote:

michael furey wrote:

Ah I see this was answered before I posted. So to contribute I'll pose another (more difficult) question: there are two bikers travelling at the same speed. One is biking alone, the other is followed closely by another cyclist drafting off of him. Do the two bikers have to exert the same amount of energy to keep going at the same speed? (FYI I don't know the answer)

I assume by "two bikers" (there are three), you mean the two out front. All things being the same (bikes, body weight, etc.)there should be no difference. The drafter is behind the cyclist and not physically connected to him. Once the air passes him, the air friction or wind resistance created by the second cyclist means naught to the first.