What will happen in this situation

  • Context: High School 
  • Thread starter Thread starter irphysics
  • Start date Start date
Click For Summary

Discussion Overview

The discussion revolves around the scenario of a man jumping inside a moving train, exploring the implications of motion, velocity, and forces involved in such an action. Participants consider both the theoretical and practical aspects of the situation, including the effects of lateral velocity and external forces like air resistance.

Discussion Character

  • Exploratory
  • Technical explanation
  • Conceptual clarification
  • Debate/contested

Main Points Raised

  • Some participants propose that if the man jumps while the train is moving, he will land in a different spot due to the train's forward motion during the time it takes him to jump.
  • Others argue that if the man is already on the train and jumps straight up, he will maintain his horizontal velocity and land in the same spot, assuming no external forces act on him.
  • A participant mentions that if the train is open-topped or if the man is on the roof, air resistance could slow him down, potentially causing him to land behind his starting point.
  • Another viewpoint suggests that if the train is turning or changing speed while the man is airborne, he will land in a different location relative to his starting point.
  • Some participants highlight the implications of constant linear speed, noting that in such cases, the man would fall back to the same spot, referencing similar scenarios in other moving vehicles.

Areas of Agreement / Disagreement

Participants express multiple competing views regarding the outcome of the jump, with no consensus reached on the effects of various conditions such as air resistance, train velocity, and direction of motion.

Contextual Notes

Limitations include assumptions about the train's motion (constant speed vs. changing speed) and the effects of external forces like air resistance, which are not fully resolved in the discussion.

irphysics
Messages
4
Reaction score
0
What will happen if a man jumps inside a train.Will the train move forward and the man land up in different place.Sorry for my bad English.
 
Physics news on Phys.org
irphysics said:
What will happen if a man jumps inside a train.Will the train move forward and the man land up in different place.Sorry for my bad English.

However long it takes for the man to jump, from the ground onto the train, the train will have moved x = vt (where t is that time and v is the velocity of the train). So yeah, the spot will have moved, and it will have moved a lot if the train is going very fast.

Furthermore, since the train has a lateral velocity and the man does not (i.e. the man does not have any velocity in the direction of the train's velocity), when the man's feet land on the train, they will be pulled with the motion of the train and he may fall over if he doesn't shift his center of gravity appropriately.

Of course, if you're riding along side the train in a horse and keeping up with it perfectly, then you'll have velocity in the direction of the train, so when you jump it will be as if you jumped from one stationary object to another (ignoring wind and air resistance).
 
Pythagorean said:
However long it takes for the man to jump, from the ground onto the train, the train will have moved x = vt (where t is that time and v is the velocity of the train). So yeah, the spot will have moved, and it will have moved a lot if the train is going very fast.

Furthermore, since the train has a lateral velocity and the man does not (i.e. the man does not have any velocity in the direction of the train's velocity), when the man's feet land on the train, they will be pulled with the motion of the train and he may fall over if he doesn't shift his center of gravity appropriately.

Of course, if you're riding along side the train in a horse and keeping up with it perfectly, then you'll have velocity in the direction of the train, so when you jump it will be as if you jumped from one stationary object to another (ignoring wind and air resistance).

Inside a train?
 
Pythagorean said:
However long it takes for the man to jump, from the ground onto the train...

I'm pretty certain the OP is talking about a person that is already riding in the train simply jumping straight up inside the train.

Not that your examples don't clearly illustrate the principles and answer the question. I wonder if the OP can figure out an answer from what you've already posted.
 
S_Happens said:
I'm pretty certain the OP is talking about a person that is already riding in the train simply jumping straight up inside the train.

Not that your examples don't clearly illustrate the principles and answer the question. I wonder if the OP can figure out an answer from what you've already posted.

yes,the man is riding train.Should i try this
 
You have to ask yourself "What is there to slow the man down during his jump?"
If there is nothing then he will keep traveling at the same speed as the train, landing on the same spot he took off. Newton's First Law
If the train is open-topped or he's standing on the roof like James Bond, then there may be some drag, caused by his movement (at 60mph) through the air, acting on his body which will slow him down a bit once he is no longer in contact with the train and he may land a short way behind his starting mark on the train.
 
Depends if the train is traveling at a constant velocity and in a straight line.
If the train is going round a bend to the left when the man jumps he will land to the right.
The amount of deflection depends depends on how much the train traveled to the left when he is airbourne.
Likewise he will land in a different spot if the train speeds up or slows down whilst he is airbourne.
 
Yeah, it's a good thing that with constant, linear speed you will fall to the same spot, else imagine the chaos if I jumped or threw something up into the air while inside a passenger jet going a smooth 600mph!
 
pallidin said:
Yeah, it's a good thing that with constant, linear speed you will fall to the same spot, else imagine the chaos if I jumped or threw something up into the air while inside a passenger jet going a smooth 600mph!

splat!
 

Similar threads

  • · Replies 10 ·
Replies
10
Views
2K
  • · Replies 2 ·
Replies
2
Views
4K
  • · Replies 8 ·
Replies
8
Views
2K
  • · Replies 11 ·
Replies
11
Views
3K
  • · Replies 34 ·
2
Replies
34
Views
5K
  • · Replies 4 ·
Replies
4
Views
2K
  • · Replies 26 ·
Replies
26
Views
5K
  • · Replies 11 ·
Replies
11
Views
5K
  • · Replies 12 ·
Replies
12
Views
2K
  • · Replies 18 ·
Replies
18
Views
2K