Question

speed cameras are used to detect motorists who break the speed limit . a number of lines 2m apart are painted on the road. as a speeding car crosses the painted lines, the camera takes two photographs,0.5 seconds apart. the speed of car in the photographs is

Answer 1

It means he crossed 2m in 0.5 sec
now, from speed =distance/time
speed of car=2m/0.5s=4m/s