Question

Two train cars are on a straight, horizontal track. One car starts at rest and is put in motion with a constant acceleration of 2m/s^2. This car moves towards a second car that is 30 away. The second car is moving away from the first car and is traveling at a constant speed of 4m/s. a.) Where will the cars collide?, b.) How long will it take for the cars to collide?

Answer 1

we need to find where the cars have gone the same distance. So,

0 + 0t + (1/2)(2)t^2 = 30 + 4t
that is,
t^2 - 4t - 30 = 0
t = 7.83

Just plug that value in for t to see where they met.

Answer 2

a.) 61.3m