Train Motion: Does it Really Move While Rotating Wheels?

  • Thread starter pinestone
  • Start date
  • Tags
    Track
In summary, the train does move despite the conflicting directions of the top and bottom points of the wheel. The key is that the center of the wheel, which represents the overall movement of the train, is moving at the same speed as the train itself. Therefore, the train moves west at a speed of 50 km/hr.
  • #1
pinestone
140
3
A train is moving west at 50 km/hr. In relationship to the tracks, the top point of the trains wheel is also moving east. However, the bottom point of the wheel is moving west. Assuming the wheel rotates at a constant speed, does the train really move at all?
 
Physics news on Phys.org
  • #2
If the train is moving west then the top of a wheel is also traveling west but at twice the speed of the train. The bottom point of the wheel is moving neither west nor east unless it is sliding on the track. Of course, the center of the wheel is moving west at exactly the same speed as the train.

I can assure you that the train does move! :)
 
  • #3
What Tide said, plus:

If the top of the wheel is moving east and the bottom is moving west, then no, the train does not move; it just sits there spinning its wheels. This of course assumes that the westbound velocity at the bottom and the eastbound velocity at the top are equal. If they're not equal, then the train moves at a rate equal to the difference of the two.
 

Related to Train Motion: Does it Really Move While Rotating Wheels?

1. What causes a train to move while its wheels are rotating?

The movement of a train is caused by the rotational force of its wheels against the tracks. This rotational force, also known as torque, propels the train forward.

2. Is it possible for a train to move without its wheels rotating?

No, in order for a train to move, its wheels must rotate. The rotation of the wheels creates the necessary force to move the train forward.

3. Does the speed of the train affect the rotation of its wheels?

Yes, the speed of the train can affect the rotation of its wheels. The faster the train moves, the faster its wheels will rotate. However, the rotation of the wheels also depends on other factors such as the weight of the train and the condition of the tracks.

4. Why do trains have multiple sets of wheels?

Trains have multiple sets of wheels to distribute the weight of the train evenly and to increase their stability. This allows the train to move smoothly and efficiently along the tracks without causing damage to the wheels or the tracks.

5. How does the rotation of the wheels affect the train's direction?

The rotation of the wheels is what allows the train to change direction. By rotating the wheels on one side faster than the other, the train can turn and follow the curvature of the tracks. This is similar to how a car turns using its front wheels.

Similar threads

B How does the Gallilean Invariance Puzzle challenge our understanding of motion?
    • Classical Physics
Replies
34
Views
2K
B How does running in a moving train affect race times?
    • Classical Physics
Replies
27
Views
2K
I On whether the motion of a Foucault pendulum bob is comparable to ballistics
    • Classical Physics
Replies
10
Views
1K
B Rotational Dynamics: Confused about the tension in this string pulling a mass up an incline
    • Mechanics
Replies
2
Views
152
I A perfectly stiff wheel cannot roll on a stiff floor?
    • Classical Physics
4
Replies
116
Views
10K
I Variation of the lightning train thought experiment
    • Special and General Relativity
Replies
21
Views
715
Forces when car wheels "lay rubber"
    • Introductory Physics Homework Help
Replies
5
Views
933
I I would like a better understanding of friction and hysteresis
    • Classical Physics
Replies
5
Views
1K
B Einstein's train-lightning scenario doesn't demonstrate relativity
    • Special and General Relativity
2
Replies
52
Views
5K
I Solving Wheel Coming to a Stop: FBD, Friction & Hysteresis
    • Mechanics
Replies
22
Views
2K

Hot Threads

Recent Insights

Back
Top