Two trains one travelling at 54 kmph and the other at 72 kmph are headed towards one an other along a straight track. When they are `1/2` km apart, both drivers simultaneously see the other train and apply their brakes. If each train is decelerated at the rate of `1 ms^(-2)` , will there be collision ?

Explanation

Distance travelled by the first train before coming to rest
`s_1=u^2/(2a)=(72xx5/18)^2//2xx1=400/2`=200 m
`=225/2`=112.5 m
Distance travelled by the second train before coming to rest
`s_2=(72xx5/18)^2//2xx1=400/2=200` m
Total distance travelled by the two trains before coming to rest =`s_1+s_2`=112.5+200=312.5 m
Because the initial distance of separation is 500 m which is greater than 312.5 m, there will be no collision between the trains.