In how many seconds will the n-th wagon pass next to me?

[PeroK]

Can you please give me one more hint please?

Does this equation help?

s= vo.t + 1/2at^2

 

[HAF]

Does this equation help?

What I did this time is this.
v_n = v_n-1 .at_n
which means a=(v_n -v_n-1) / t_n

and that's what I put in equation s=v_n-1.t_n + 1/2.a.t_n²

what I got is this t_n = 2s/(v_n + v_n-1)

Can this somehow help me? I'm really sorry for my stupidness but I can't figure it still out.

 

[PeroK]

What I did this time is this.
v_n = v_n-1 .at_n
which means a=(v_n -v_n-1) / t_n

and that's what I put in equation s=v_n-1.t_n + 1/2.a.t_n²

what I got is this t_n = 2s/(v_n + v_n-1)

Can this somehow help me? I'm really sorry for my stupidness but I can't figure it still out.

It's not a good idea to consider intermediate speeds. That is where the complications arise. $v_0 = 0$ for the motion of the train.

 

[HAF]

It's not a good idea to consider intermediate speeds. That is where the complications arise. $v_0 = 0$ for the motion of the train.

And what is your advise?

 

[PeroK]

And what is your advise?

$s = \frac12 at^2$

 

[HAF]

$s = \frac12 at^2$

Nope. I can't figure anything out. I will make a break for a while and then I will try it again because now I can't do it.

Thank You you for everything. I really appreciate it.

 

[mfb]

Plug in L for the first wagon.
Plug in nL for the first n wagons and solve for the new time. You should get $t \sqrt n$. From there you can take the difference between adjacent wagons.

 

[HAF]

Plug in L for the first wagon.
Plug in nL for the first n wagons and solve for the new time. You should get $t \sqrt n$. From there you can take the difference between adjacent wagons.

Plug it where? In s=1/2a.t^2?

 

[HAF]

Plug in L for the first wagon.
Plug in nL for the first n wagons and solve for the new time. You should get $t \sqrt n$. From there you can take the difference between adjacent wagons.

Thank You guys! I finally got it!

 

[DaveC426913]

So guys I talked to my teacher and he clarified few important things.

1. At the beginning I'm standing in front of the first wagon.

Answer:
After one second, you are dead.


Sorry. Couldn't resist. Carry on.