Does it need to fly forward? Or just need to fly to keep at the same position as usual?
$\begingroup$
$\endgroup$
5
-
$\begingroup$ the flower is in the train? $\endgroup$– TanMathCommented Oct 26, 2015 at 6:57
-
1$\begingroup$ Hi Gstestso. The duplicate I've suggested is a helicopter not a humming bird, but the physical principles involved are the same. $\endgroup$– John RennieCommented Oct 26, 2015 at 7:49
-
$\begingroup$ @John Rennie: Hi, sir; one thing I need to clear: why've you marked this as the duplicate of another duplicate? Why not just mark it the duplicate of Helicopter in an Elevator & links therein? $\endgroup$– user36790Commented Oct 26, 2015 at 7:54
-
$\begingroup$ @user36790: the helicopter in an elevator question is really about just up and down motion, while the question I've linked addresses sideways motion as well - in general trains only go sideways and not up and down :-). Actually I wouldn't have marked the Closed Box question as a duplicate for this reason, but I'm not sure it's worth trying to get it reopened now. $\endgroup$– John RennieCommented Oct 26, 2015 at 8:13
-
$\begingroup$ @John Rennie: Definitely, it need not be reopened as the linked ones answer this. However, if the linked one is a duplicate of helicopter in the elevator, then definitely it ought be marked duplicate by the same question. And as you said if the helicopter in the elevator is asking up-down motion, why was the linked one addressing sideways motion marked as duplicate of helicopter in the elevator? Okay, no more argument; OP, I think, got his answer; that's it:) $\endgroup$– user36790Commented Oct 26, 2015 at 8:24
Add a comment
|
2 Answers
$\begingroup$
$\endgroup$
1
The key part to this question is the fact that although the bird is supported by the air (which does move with the train), it is not floating in it. The bird must use its wings to overcome gravity (which is similar to an upward acceleration of the train).
If an additional acceleration forward is introduced, the birds wings must do additional work or it will move through the air until the rear wall of the train reaches it.
answered Oct 26, 2015 at 7:14
-
$\begingroup$ First paragraph is irrelevant, because it seems that this knowledge is demonstrated by OP in the sentence "Or just need to fly to keep at the same position as usual?" $\endgroup$– TanMathCommented Oct 26, 2015 at 7:25
$\begingroup$
$\endgroup$
2
The hummingbird would need to fly forward because the flower is in the train and will move forward and since the hummingbird is not part of the train (i.e. attached to the train), it will need to move forward to catch up. Otherwise, it will just hit the rear end of the train car in which the flower is in.
-
3
-
1$\begingroup$ Not my downvote, but your answer doesn't describe the physical principles involved at all. $\endgroup$ Commented Oct 26, 2015 at 7:46