m/s Suppose the policeman catches thethief after t seconds. Distance covered by the policeman in t seconds = 100 m + Distance covered by the thief in t seconds ∴
25
9
t=100+
20
9
t ⇒
5
9
t=100 ⇒t=
100×9
5
=180seconds Therefore, the distance run by thethief before the policeman overtakes him=