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 before coming to rest `s_(1)=u^2/(2a)=(72xx 5/(18))^(2)//2 xx 1=(400)/(2)=200m`
`=(225)/(2)=112.5m`
Distance travelled by the second train before coming to rest
`s_(2)=(72 xx (5)/(18))^2 //2 xx 1=(400)/2=200m`
Total distance travelled by the two trains before comming to rest `=s_(1)+s_(2)=122.5+200=312.5m`
Because the initial distance of separation is 500m. Which is greater than 312.5m, then will be no collision between the trains.