A police jeep is chasing a culprit going on a motorbike. The motorbike crosses a turning at a speed of 72 km h-1. The jeep follows it at a speed of 90 km h-1, crossing the turning 10 s later than the bike. The distance (in km) from turning point at  which the police catch the culprit is ________ .

vp=90kmh−1=25ms−1,vc=72kmh−1=20ms−1In 10 s  culprit reaches point B from A. Distance covered by culprit,s=vt=20×10=200m.At time t = 10 s, the police jeep is 200 m behind the culprit. Relative velocity between jeep and culprit is 25−20=5ms−1Time =sv=2005=40sIn 40 s, the police jeep will move from A to a distance s where, s=vt=25×40=1000m=1.0km away. The jeep will catch the bike 1 km far from the turning point.