Fly in a Train: Exploring Physics Inside a Moving Train

In summary, the conversation discusses how an object, specifically a fly, behaves when suspended inside a moving train. The fly appears to move towards the back of the train when the train starts moving, but this is actually an illusion caused by the train's acceleration. The fly remains stationary with respect to the ground and only appears to move due to the first law of motion. The air supports the fly and allows it to accelerate, but it does not have to fly at the same speed as the train to appear stationary within the train. Overall, the conversation highlights the principles of inertia and acceleration in relation to objects in motion in a train.
  • #1
semc
368
5
Fly in a train!

Hey guys, i was wondering what happens if an object is suspended in mid air inside a moving train? Why doesn't the object just fly back to the back of the train when the train starts moving? I mean it has got no contact with the train so it will not have the velocity of the train right??
 
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  • #2


semc said:
I mean it has got no contact with the train
How is it suspended?
 
  • #3


semc said:
Why doesn't the object just fly back to the back of the train when the train starts moving?
It actually does. More precisely the fly remains stationary with respect to the ground while train accelerates so it appears to be moving back to an observer in the train.It is a consequence of the first law.
 
Last edited:
  • #4


Doc Al said:
How is it suspended?

its just like a fly in a train

bp_psy said:
It actually does. More precisely the fly remains stationary with respect to the ground while train accelerates so it appears to be moving back to an observer in the train.It is a consequence of the first law.

so the fly will go to the back of the train when it accelerate? So how is it possible to see a fly flying around in a train.
 
  • #5


semc said:
So how is it possible to see a fly flying around in a train.
On a trip of any significant length, how much time does the train actually spend accelerating?
 
  • #6


semc said:
its just like a fly in a train
So what supports the fly? The air, of course.

so the fly will go to the back of the train when it accelerate? So how is it possible to see a fly flying around in a train.
In order for the fly to accelerate, a net force must act on it. (It's got to push against the air.) If the train lurches forward, the fly will appear to be pushed toward the rear of the train unless it compensates. (Which it can easily do. Flys zoom all over the place creating greater accelerations than you are likely to experience on a train.) Once the train stops accelerating, everything is back to normal.
 
  • #7


Doc Al said:
So what supports the fly? The air, of course.
Sorry i don't quite get it. So what if the air support the fly? It has got the same speed as the train just like us when we are inside a train?

Wow so the fly doesn't have to fly at the same speed as the train to appear stationary?
 
  • #8


semc said:
Sorry i don't quite get it. So what if the air support the fly?
Something must exert a force on the fly to accelerate it.
It has got the same speed as the train just like us when we are inside a train?
Not sure what you mean. Flys buzz around.
Wow so the fly doesn't have to fly at the same speed as the train to appear stationary?
What do you mean by "fly" at the same speed as the train? To appear stationary within the train, it must have the same speed as the train.
 

Related to Fly in a Train: Exploring Physics Inside a Moving Train

1. What is the concept behind "Fly in a Train: Exploring Physics Inside a Moving Train"?

The concept behind "Fly in a Train" is to explore the principles of physics, such as inertia, force, and motion, through the experience of a fly inside a moving train. The train serves as a reference frame for the fly, and by observing the fly's movement, we can understand the effects of different forces acting on it.

2. How does the movement of the train affect the fly inside?

The movement of the train affects the fly in several ways. Firstly, the train's motion creates a force called inertia, which causes the fly to resist changes in its state of motion. Secondly, the train's acceleration or deceleration can also affect the fly's movement, as it experiences a force in the direction of the train's movement. Finally, the fly may also experience air resistance due to the train's speed, which can impact its movement.

3. Can this experiment be performed in any type of train?

Yes, this experiment can be performed in any type of train, as long as it is in motion. However, certain factors like the train's speed and the smoothness of its movement may affect the accuracy of the observations.

4. How can this experiment be used to understand the laws of physics?

This experiment can be used to understand the laws of physics by allowing us to observe and analyze the effects of different forces on the fly inside the train. By understanding how the fly's movement changes in relation to the train's movement, we can learn more about the principles of inertia, force, and motion.

5. Is "Fly in a Train" suitable for all ages?

Yes, "Fly in a Train" can be enjoyed by people of all ages. It is a fun and interactive way to learn about physics and can be adjusted to different levels of understanding. Younger children may simply observe the fly's movement, while older children and adults can delve deeper into the scientific concepts behind it.

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