# Homework Help: Newton's second law

1. Oct 2, 2008

### Jennifer001

1. The problem statement, all variables and given/known data

A 50,000 kg locomotive is traveling at 60.0 when its engine and brakes both fail.

How far will the locomotive roll before it comes to a stop?

I'm completely lost and i dont know how to get started on this question

2. Oct 2, 2008

### LowlyPion

F = m*a

If there is no braking, there is no force. No force means no deceleration.

Is that the entire statement of the problem?

3. Oct 2, 2008

### Jennifer001

yes thats the entire question

4. Oct 2, 2008

### Jennifer001

for F=m*a there is no acceleration because its alrdy travelling at 60m/s sorry i left that "m/s" out of the question

5. Oct 2, 2008

### LowlyPion

Better hope there is a lot of track then.

6. Oct 2, 2008

### Sakha

If the problem doesn't state a friction force involved, or any other type of force involved, then the train will keep moving until...some force interact with it.

7. Oct 3, 2008

### tiny-tim

Re: newton's FIRST law

Yup!

btw, this isn't a Newton's second law problem, but a Newtons first law problem …

a body on which no forces act continues to move with uniform velocity.