# Train speed/time problem

• Sep 20th 2009, 08:10 AM
clay10
Train speed/time problem
I got a packet over the weekend with all trigonometry questions but there's one algebra problem that I'm stuck on, although it's probably really simple. It's referred to a previous problem asking what the angle of elevation and vertical rise but that probably doesn't matter for this question.

A 2 mile train is traveling at 10 MPH. To the nearest minute, how long will it take the train to completely pass through a tunnel that is exactly one mile long?

• Sep 20th 2009, 08:21 AM
CaptainBlack
Quote:

Originally Posted by clay10
I got a packet over the weekend with all trigonometry questions but there's one algebra problem that I'm stuck on, although it's probably really simple. It's referred to a previous problem asking what the angle of elevation and vertical rise but that probably doesn't matter for this question.

A 2 mile train is traveling at 10 MPH. To the nearest minute, how long will it take the train to completely pass through a tunnel that is exactly one mile long?

The train starts passing through the tunnel when the front of the train enters the tunnel, and finishes when the end of the train leaves the tunnel.

So how far is the front of the train from the start of the tunnel when the end of the train leaves the tunnel? How long did it take the front of the train to cover this distance?

CB
• Sep 20th 2009, 08:47 AM
clay10
so the train covered 5 miles total, but 3 miles for the front to enter and exit the tunnel.

10 miles/60 minutes = 3 miles/x minutes

x= 18 minutes

I was making this harder than it was...
• Sep 20th 2009, 08:56 AM
CaptainBlack
Quote:

Originally Posted by clay10
so the train covered 5 miles total, but 3 miles for the front to enter and exit the tunnel.

10 miles/60 minutes = 3 miles/x minutes

x= 18 minutes

I was making this harder than it was...

No the front of the train has moved three miles between the front entering the tunnel and the end leaving the tunnel.

CB
• Sep 20th 2009, 12:23 PM
clay10
That's what I mean to say. I'm assuming I got the right answer though...
• Sep 20th 2009, 01:31 PM
CaptainBlack
Quote:

Originally Posted by clay10
That's what I mean to say. I'm assuming I got the right answer though...

3 tenth of an hour = 18 min.

yes.

CB