- #1
argpirate
- 7
- 0
Homework Statement
A passenger train is traveling at 27 m/s when the engineer sees a freight train 366 m ahead of his train traveling in the same direction on the same track. The freight train is moving at a speed of 5.9 m/s.
(a) If the reaction time of the engineer is 0.39 s, what is the minimum (constant) rate at which the passenger train must lose speed if a collision is to be avoided?
Homework Equations
dx=vt+1/2at^2
The Attempt at a Solution
I tried to set the dx=dx and solve for t using the quadratic equation. Then, since we are solving for minimum maginitude of decceleration I set the discriminant (containing 'a') equal to zero so I would get the smallest acceleration magnitude and a real time. But it was marked wrong.