A fly is "sitting" on the inside wall of a closed bottle. The bottle is standing on a scale. The fly "leaves" the wall and starts flying around inside the bottle. Does the weight that scale shows increase, decrease or remain unchanged?

Question

anonymous · Answer

remains the same..i guess...cuz flyinf wont change d weight

anonymous · Answer

The weight remains the same. For a weight to act, the object must exert a force or may exert pressure on another object or gas

anonymous · Answer

Thank you both :)

anonymous · Answer

It will remain constant only if the fly moves with constant speed. If it moves ,for eg ,up with increasing speed, the scale will go up.

shane_b · Answer

Assuming the scale is sensitive enough to even measure a difference I believe @Diwakar's answer is the most correct.  

Whether it's sitting on the wall or flying around the bottle it must exert a downward force to counteract gravity.  If it's accelerating the force acting on the scale will obviously change...at a constant speed it will be constant.

anonymous · Answer

i think the wight will decrease due to the fact that the bottle + the fly read same value but now the fly is now in air and not on the bottle . so there for the wight will change

shane_b · Answer

@emekaojei: The fly, even in the air above the bottle, must exert a downward force when flying.

anonymous · Answer

ok. than sir

anonymous · Answer

I think my question was a little unclear as written. "When the fly is "sitting" on the wall, the scale shows weight A. Does it still show weight A when the fly starts flying around" Would've been a better explanation of the problem. Are you guys still at the same conclusion?

shane_b · Answer

My answer still stands :)