Two trains, one traveling at 72 km/h and the other at 144 km/h, are headed toward one
another along a straight, level track. When they are 950 m apart, each engineer sees the
other’s train and applies the brakes. This causes each train to have an acceleration against
the train’s direction of motion with the magnitude of 1 m/s2. (a) Calculate the distance
required for each train to come to a complete stop and based on this result conclude
whether there will be a collision? Also calculate the time required for each train to come
to a stop. (b) Provide an x(t),
!
v(t), and
!
a(t) diagra

Question

Two trains, one traveling at 72 km/h and the other at 144 km/h, are headed toward one
another along a straight, level track. When they are 950 m apart, each engineer sees the
other’s train and applies the brakes. This causes each train to have an acceleration against
the train’s direction of motion with the magnitude of 1 m/s2. (a) Calculate the distance
required for each train to come to a complete stop and based on this result conclude
whether there will be a collision? Also calculate the time required for each train to come
to a stop. (b) Provide an x(t),
!
v(t), and
!
a(t) diagra

anonymous · Answer

There will be a collision.
You can find the time using
$$\large \Delta v=at$$
then find distance using
$$\large \Delta x = vt-.5at^2$$