# Help Relative Velocity

1. Oct 4, 2016

### kidgt23

1. The problem statement, all variables and given/known data
A person on a train watches a car approaching a railway crossing ahead on his track. It appears that the car’s driver has fallen asleep and will not slow down. The train is traveling north‐east at 100km/h while the car is going west at 80km/h. The train is 4 km and the car is 3km from the crossing. I) What is the velocity of the car relative to the train. Pick the train travel direction (North‐ East) as the +x direction and the perpendicular direction (North‐west) as the +y direction II) Where will the train be when the car gets to the crossing, will they collide? III) Find the acceleration of the car required to cause a collision. IV) In the reference frame of the train rider, what is the acceleration.

2. Relevant equations

3. The attempt at a solution

2. Oct 4, 2016

### BvU

Hi kid,

Is there a question here ? PF has a specific culture (read the guidelines) asking something from you ...

3. Oct 4, 2016

### kidgt23

could u solve it

4. Oct 4, 2016

### PeroK

In order to get help you need to show your best attempt to solve the problem and explain where you get stuck. We can just do the problem for you.