Need Help with Physics Problem...?

Question

Amtrak's 20th-Century Limited is in route from Chicago to New York at 112 km/h, when the engineer spots a cow on the track. The train brakes to a halt in 2.3 min, stopping in front of the cow.

a) What is the magnitude of the train's (constant) acceleration?

_______m/s^2 <-----(0.22m/s^2) Correct

b) What is the direction of the acceleration?

- eastward

- westward <-----Correct

- southward

- northward

c) How far was the train from the cow when the engineer first applied the brakes?

______km

I have a) and b) correct but c) I can't figure out.

Answers a) and b) was done by Sturm Vogel, Thanks again

Answer 1

Use the kinematic equation - Vf2 = Vi2 + 2ad

Answer 2

Allow me to make things right this time.

c) xf = xi + vi*t + ½*a*t²

= 0 m + (31.1 m/s x 138 s) + (0.5 x -0.22 m/s² x (138 s)²)

= 0 m + 4291.8 m - 2094.84 m

= 2196.96 m

If that is not the right answer, then inform me of what it is.

EDIT: To the person below me: I used that the first time, and I got the same answer.

http://answers.yahoo.com/question/index;...