A train takes 6 seconds to pass a 50m long platfrom at speed of 72km/h

[Lexadis]

[solved]A train takes 6 seconds to pass a 50m long platfrom at speed of 72km/h

I did the sum, but I'm not sure I have the correct answer (and there's no answer guide either T.T) So if you guys can please help me out I'll be really really helpful Thanks in advance! ^_^

So here it goes:

A train takes 6 seconds to pass a 50m long platfrom at speed of 72km/h


--->Convert 72km/h to m/s.

\(\displaystyle \frac{72 *1000}{1*60*60}=50ms^{-1}\)

-->Find the distance traveled in 6 secs.
\(\displaystyle Speed = \frac{distance}{time}\)

\(\displaystyle 50ms^{-1} = \frac{d}{6s}\)

\(\displaystyle distance = 300m\)

--> Find the length of the train
\(\displaystyle 300m-50m = 250m\)

 

[Quaid]

I did the sum, but I'm not sure I have the correct answer (and there's no answer guide either T.T) So if you guys can please help me out I'll be really really helpful Thanks in advance! ^_^

So here it goes:

A train takes 6 seconds to pass a 50m long platfrom at speed of 72km/h


--->Convert 72km/h to m/s.

\(\displaystyle \frac{72 *1000}{1*60*60}=50ms^{-1}\)

-->Find the distance traveled in 6 secs.
\(\displaystyle Speed = \frac{distance}{time}\)

\(\displaystyle 50ms^{-1} = \frac{d}{6s}\)

\(\displaystyle distance = 300m\)

--> Find the length of the train
\(\displaystyle 300m-50m = 250m\)

Hi.

You set up the speed conversion correctly, but check your arithmetic. 50 m/s is not the right value.

Also, how do you interpret the meaning of the phrase "to pass a 50m platform"?

Let's say that we're watching this train move from left to right. Does the time interval begin when the front of the train reaches the left end of the platform and end when the back of the train leaves the right end of the platform?

Cheers :cool:

 

[Lexadis]

Oh got it, thank you very much I really don't understand these kinds of speed questions very much, which involves a bit of physics too ;_;