A thief in a stolen car passes through a police check post at his top speed of 90kmh-1. A motorcycle cop, reacting after 2 s, accelerates from rest at 5 ms-2. His top speed being 108kmh-1. Find the maximum separation between policemen and thief.

90 km/h=90×518=25 m/s108 km/h=108×518=30 m/sAt maximum separation their velocities are same.∴ Velocity of motorcycle =25 m/sorat =25or t=5 sBut thief has travelled up to 7 s.s1= displacement of thief=v1t1=25×7=175 ms2= displacement of motorcycle=12×a2t22=12×5×(5)2=62.5 m∴ Maximum separation=s1-s2=112.5 m